Updates from BBC correspondents in Ukraine: Orla Guerin on the road, Sarah Rainsford in Dnipro, Fergal Keane in Lviv, and Lyse Doucet, Paul Adams, Nick Beake and James Waterhouse in Kyiv
World's largest aircraft destroyed, Ukraine's foreign minister says
The world's largest aircraft - the Antonov An-225 - has been destroyed in the Russian advance, Ukraine's Foreign Minister Dmytro Kuleba says.
The plane was designed and built during the final years of the Soviet Union. It is so big the plane's cargo hold is as long as the Wright brothers’ first flight.
It was built to transport space shuttles but in recent years has rarely taken to the skies.
Police in St Petersburg detained anti-war protesters todayImage caption: Police in St Petersburg detained anti-war protesters today
Police have detained more than 900 people protesting against the invasion Ukraine in 44 cities across Russia today, according to data released just now by an independent monitoring group.
The OVD-Info group says it brings the total number of anti-war protesters detained in Russia to over 4,000 since the conflict began four days ago.
The BBC has not been able to independently verify either figure.
Today's protests coincided with the seventh anniversary of the murder of opposition politician and Putin critic Boris Nemtsov.
Demonstrators in Moscow have been detained today at an improvised memorial near the Kremlin site where Nemtsov was shot.
One of the largest demonstration sites is in St Petersburg, where photographs show police detaining some of the several thousand protesters who have gathered in the city's centre.
AFPCopyright: AFP
A protester clashes with police in St Petersburg todayImage caption: A protester clashes with police in St Petersburg today
AFPCopyright: AFP
Four police officers carrying one St Petersburg demonstratorImage caption: Four police officers carrying one St Petersburg demonstrator
AFPCopyright: AFP
A protester being detained today in central MoscowImage caption: A protester being detained today in central Moscow
Today’s biggest developments
AFPCopyright: AFP
A Ukrainian fighter takes the automatic grenade launcher from a destroyed Russian military vehicle after the fight in KharkivImage caption: A Ukrainian fighter takes the automatic grenade launcher from a destroyed Russian military vehicle after the fight in Kharkiv
If you’re just joining us, here’s a look back at some of today’s biggest developments:
President Vladimir Putin says he has ordered the Russian military to put its nuclear forces on "special alert" in response to what he described as Nato “aggression”
The move - which does not mean Russia intends to use the weapons - has been widely condemned, with the US calling it “totally unacceptable”, and Nato’s chief describing it as “dangerous” and “irresponsible”
Ukrainian and Russian delegations are set to meet on the Belarus border for talks, according to Ukraine’s President Volodymyr Zelensky
The number of people fleeing Ukraine has now reached 368,000, according to the latest UN figures
European countries are continuing to take action against Russia, with many closing their airspace to Russian flights in recent hours
Putin nuclear warning 'dangerous' - Nato chief
The chief of Nato says Vladimir Putin's order to the Russian military to put its nuclear forces on a higher level of alert is "dangerous" and "irresponsible".
It adds to the Russian leader's aggression over Ukraine, Jens Stoltenberg says.
"Of course when you combine this rhetoric with
what they are doing on the ground in Ukraine - waging war
against an independent, sovereign nation, conducting
full-fledged invasion of Ukraine - this adds to the seriousness
of the situation," he tells CNN.
Watch: Ukrainians take up arms to fight invasion
Video content
Video caption: Ukraine conflict: Citizen volunteers take up arms to fight Russian invasionUkraine conflict: Citizen volunteers take up arms to fight Russian invasion
As the Russian invasion continues, thousands of ordinary Ukrainians are volunteering to fight to defend their neighbourhoods, despite many having no previous military experience.
Men between the ages of 18 and 60 are banned from leaving the country and have been urged to fight.
The Ukrainian defence minister says that 25,000 guns have been handed over to territorial defence members in the Kyiv region alone.
The BBC Ukrainian service visited one centre distributing weapons in the capital Kyiv.
Russia trying to apply pressure - Ukraine foreign minister
Ukrainian Foreign Minister Dmytro Kuleba has said if Russia uses nuclear weapons against Ukraine it will be a "catastrophe for the world".
"But it will not break us down," he claimed.
His comment came after Russian President Vladimir Putin ordered the Russian military to put its nuclear forces on "special alert".
Speaking at a news conference, Kuleba said: "This order by President Putin came shortly after the announcement was made about two delegations ready to meet [for talks].
"We see this announcement or this order as an attempt to raise the stakes and to put additional pressure on the Ukrainian delegation.
"But we will not give in to this pressure. We will approach these talks with a very simple approach. We go there to listen [to what] what Russia has to say and we will tell them what we think of all this."
He added: "Ukraine is not falling. We are bleeding, but we continue to successfully defend ourselves."
'At no point has Russia been under threat from Nato' - US
At no point has
Russia been under threat from Nato, says White House Press Secretary Jen Psaki, in response to President Putin putting Russia's nuclear forces on "special alert".
Putin blamed Nato leaders for allowing "aggressive statements" to be made against Russia. But Psaki said it was a familiar response from Russia's president.
"We've seen him do this time and time again. At no point has
Russia been under threat from Nato, has Russia been under threat
from Ukraine," she told ABC News.
"This is all a pattern from President Putin and we're going
to stand up to it.
"We have the ability to defend ourselves, but
we also need to call out what we're seeing here from President
Putin," she added.
In pictures: The aftermath of battle in Kharkiv
Getty ImagesCopyright: Getty Images
A Russian armoured personnel carrier (APC) burning in KharkivImage caption: A Russian armoured personnel carrier (APC) burning in Kharkiv
Regional governor Oleh Synehubov said the city was now rid of Russian troops - after street-to-street fighting.
In these pictures you can see the aftermath of the fierce fighting which took place.
Getty ImagesCopyright: Getty Images
An Ukrainian Territorial Defence fighter takes the automatic grenade launcher from a destroyed Russian infantry mobility vehicleImage caption: An Ukrainian Territorial Defence fighter takes the automatic grenade launcher from a destroyed Russian infantry mobility vehicle
Getty ImagesCopyright: Getty Images
Ukrainian fighters test the grenade launcherImage caption: Ukrainian fighters test the grenade launcher
Getty ImagesCopyright: Getty Images
Volunteers have collected food for those who need itImage caption: Volunteers have collected food for those who need it
Getty ImagesCopyright: Getty Images
Ukrainian Territorial Defence fighters patrol the streetsImage caption: Ukrainian Territorial Defence fighters patrol the streets
Analysis
Nuclear warning is exactly what Nato feared
Frank Gardner
BBC Security Correspondent
Russia’s announcement that its nuclear deterrent has
been put on "special alert" is a sign of both President Putin’s anger at the
West’s anti-Russian sanctions and his enduring paranoia that his country is
under threat from Nato.
His move has certainly got the West’s attention. This
sort of escalation is exactly what Nato military planners feared and it’s why
the alliance has repeatedly announced it will not be sending troops to help
Ukraine repel its Russian invaders.
But Russia’s offensive is not going entirely to plan. On day four, not a single major Ukrainian city is in Russian hands and the Russians appear
to be taking heavy casualties.
This will be causing some frustration and
impatience in Moscow. And it’s hard to see the proposed peace talks on the Belarus
border reaching a deal that works for both Moscow and Kyiv.
Putin wants Ukraine
fully back into its sphere, the Zelensky government wants it to stay
independent. Short of partition, that doesn’t leave much room for compromise.
So, coupled with today’s nuclear-tipped warning to the
West to back off, we are likely to see an intensification of Russia’s offensive
on Ukraine in coming days, with even less regard for civilian casualties than
has been shown so far.
More from Kharkiv: Full statement from regional governor
Getty ImagesCopyright: Getty Images
A Ukrainian Territorial Defence fighter examines a destroyed Russian infantry mobility vehicle in KharkivImage caption: A Ukrainian Territorial Defence fighter examines a destroyed Russian infantry mobility vehicle in Kharkiv
As we've been reporting, Kharkiv officials say they have repelled a Russian attack, and are in charge of Ukraine's second city.
Here's a fuller translation of the statement from Kharkiv regional governor Oleh Synyehubov. The BBC has been told Kharkiv is under Ukrainian control, but we cannot verify his other claims.
"The control over Kharkiv is
completely in our hands! Armed forces of Ukraine, the national police, the territorial defence forces are working: they are clearing the city of the
enemy.
"The
Russian enemy is completely demoralised. Right in the city, inside Kharkiv, a
group of five to 10 people have surrendered to the Ukrainian army. As soon as they
see at least one representative of the armed forces of Ukraine, they surrender.
"As for the situation in the wider region, here’s
what is happening now: Chuhuiv [another city] is
completely under control of the Ukrainian army, Ukrainian flags are hanged on
the administrative buildings.
"The
offensive of the Russian aggressor is ongoing in the following directions: from
Lyptsi, Vovchansk, and Belhorod.
"We see separate regiments of [Russian] military
vehicles. The armed forces of Ukraine are in their positions in active
fighting."
RAF jets step up patrols on Russian border
Emma Vardy
Reporting from an RAF Voyager above Poland
BBCCopyright: BBC
We are in an RAF Voyager over Poland - about 50 miles from the
Russian border - watching the UK’s Typhoon fighter jets refuelling in the air
beside us.
British military jets have significantly stepped up their patrols
since Russian forces invaded Ukraine, as part of the Nato mission to defend
Europe - although the exercise is not related to President Putin's recent nuclear deterrent announcement.
The RAF Typhoons are effectively policing the skies in Poland and
Romania to deter any further Russian aggression, demonstrating they have a
strong presence here.
While these RAF jets are close to Russian airspace they are also
able to gather information on the radar about what Russian military aircraft
are in the air, and what they’re doing.
If there were to be a Russian military incursion into a Nato country, the RAF crews tell me these fighter jets would be within their rights
to engage them.
But for now it’s hoped the increased presence of Nato forces in the
air will send a clear message to Moscow.
Officer Mike Udall tells me: "It’s partly reassurance to show Nato allies we’re there with them,
to maintain integrity of the airspace, make sure we’ve got a good understanding
of who’s flying where and to react to any emerging threats.
"There’s a very human element to is and we all feel that, we all
watch the news, but our role is to be there and do our own job and contribute
in the way we can."
US calls Putin's nuclear move 'totally unacceptable'
The US has responded to President Putin's order putting Russia's nuclear forces on a "special" state of alert.
The move makes it easier to launch weapons - but our security correspondent Gordon Corera said it was a way for Russia to send a warning to Nato, rather than signalling an intent to use them.
The US Ambassador to the United Nations, Linda Thomas-Greenfield, called the move "unacceptable" in an interview with CBS News.
"It means that President Putin is continuing to escalate
this war in a manner that is totally unacceptable and we have to
continue to stem his actions in the strongest possible way,"
she said.
BreakingUkrainian president says delegations to meet on Belarus border
Ukrainian president Volodymyr Zelensky has released a statement following his conversation with Belarusian president Alexander Lukashenko earlier today.
“We agreed that the Ukrainian delegation would meet with the Russian delegation without preconditions on the Ukrainian-Belarusian border, near the Pripyat River," it read.
“Alexander Lukashenko has taken responsibility for ensuring that all planes, helicopters and missiles stationed on Belarusian territory remain on the ground during the Ukrainian delegation's travel, talks and return.”
Zelensky had earlier said he would not meet a Russian delegation on Belarusian territory because Russia's invasion was launched in part from Belarus.
Neither Russia nor Belarus have issued any statements about potential talks.
Russian move does not signal intent to use nuclear weapons
Gordon Corera
Security correspondent, BBC News
President Putin has ordered his military command to put nuclear forces on a "special" state of alert.
This is after what Moscow calls "aggressive statements" by Nato countries.
Russia's leader had already issued a coded warning that he was willing to use nuclear weapons as he began his invasion of Ukraine.
Last week, he warned that "whoever tries to hinder us" would see consequences "you have never seen in your history".
These words were widely interpreted as signalling a threat to use nuclear weapons if the West stood in his way.
The very public shift to high alert status is a way for Moscow to send a warning. Moving to alert status is likely to make it easier to launch weapons more quickly. But it does not mean there is a current intent to use them.
Russia has the largest stockpile of nuclear weapons in the world but also knows that Nato also has enough to destroy Russia if they were used.
But the aim is likely to try and deter Nato support for Ukraine by creating fears over how far he is willing to go and creating ambiguity over what kind of support for Ukraine he will consider to be too much.
BreakingPutin puts Russia's strategic nuclear force on 'special alert'
Russian President Vladimir Putin has ordered the Russian military to put its nuclear forces on "special alert" - the highest level of alert for Russia's Strategic Missile Forces.
Speaking to top military officials, including Defence Minister Sergei Shoigu, he said Western nations had taken "unfriendly actions" towards Russia and imposed "illegitimate sanctions".
We'll bring you an assessment of this move shortly.
'Mom, I'm scared, save me now': The view from Kharkiv
Viktoriia Zhuhan
BBC Ukrainian
Here's some more of what we're hearing from civilians on the ground in Kharkiv.
One 34-year-old woman said she spent last night in the basement of her apartment block with around 35 others.
"We were
lucky last night. A blast hit the road next to our block but it
didn’t hit our block," she said.
"Later, we found out that two pedestrians had been killed
and another wounded. The wave of the blast was so strong that my ears popped [like when you land in a plane] even though I was sitting in the
basement.
"Just before
the blast our neighbour down in the basement was instructing their two young
kids aged three or four what to do if there was an explosion.
"Listening to this was
horrific, my hairs were standing on end at the thought that three-year-old children
were having to be taught what to do during shelling.
"Throughout
the night one young girl kept waking up her mum. She’d sit up crying screaming: 'Mom, I’m scared, please save me, save me now.'
"She only calmed down by the morning after her mum had sat holding her all through the night."
She said that, even though Ukrainian forces now control Kharkiv, she continues to hear blasts and that the offensive against the city appears to be ongoing.
"The
reserve army volunteers are doing a great job," she said.
"I’m glued to my phone but when
the connection goes down I get a little panicky, because then I don’t know how
my loved ones and friends are getting on in other parts of the city.
"Every
hour I look outside [above ground] to connect to the phone network and
internet and call them, though it’s a risky thing to do. The tension here is
horrible, but so far we are all holding on.”
Watch: Ukrainians create road blocks with sandbags
A video posted on social media appears to show defiant Ukrainians chanting and putting sand into bags to create road blocks.
"I've never seen such unity before. Everyone's loading, everyone's doing their best. Lots of bags. Glory to Ukraine,” a man can be heard saying.
The crowd responds by chanting: "Glory to heroes!" and "Glory to our nation!"
The BBC was unable to independently verify the footage, which was said to have been filmed in Kryvyi Rih - President Volodymyr Zelensky’s hometown.
100,000 at pro-Ukraine, anti-war protest in Berlin
GETTCopyright: GETT
As Germany announces a huge increase in defence spending (see below and 11:04 GMT post) German police say more than 100,000 people are taking part in a protest against the Russian invasion in Berlin.
Demonstrators have filled a large area between the Brandenburg Gate and the Victory Column / Siegessäule and more people are arriving all the time. They say the crowd could end up reaching Alexanderplatz, three kilometres away.
Earlier this week, Germany also confirmed it would be sending 1,000 anti-tank weapons and 500 Stinger missiles to Ukraine.
ReutersCopyright: Reuters
ReutersCopyright: Reuters
ReutersCopyright: Reuters
UK foreign secretary welcomes German plans to spend more on defence
Liz Truss reacts to the earlier news that Germany will now meet the Nato defence spend target, which is 2% of national GDP...
And here's more from the civilians we've spoken to on the ground in Kharkiv, where Ukrainian forces have repelled a Russian attack.
One university professor in his fifties said there were tanks fighting only a few kilometres from his home and that some of the street fighting was even closer.
"We
are staying in our house with a cellar," he said.
"It’s my wife and me, two sons, and my 80-year-old mom. We keep the boys in the cellar most of the
time.
"We have
electricity, warm home, water, and connectivity.
"Not everyone is this lucky. We
called our friend to join us – she has a new-born and a toddler. But she can’t
take a risk to try and get to us through the whole town."
He said he's ethnically Russian and that Russian is his first language but that he is in the process of learning Ukrainian.
"I feel this is the right thing to do," he said.
"I
started two or three years ago to use it at work, and recently started speaking
Ukrainian in private conversations."
He added that he also believed that Ukrainian forces have regained full control of Kharkiv - as the city's governor has claimed.
"Even the
groups that entered the city were killed or destroyed as far as I know," he said.
"Even when
they were here, they just did a breakthrough, they didn’t control the city.”
Live Reporting
Edited by Owen Amos
All times stated are UK
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AFPCopyright: AFP A Ukrainian fighter takes the automatic grenade launcher from a destroyed Russian military vehicle after the fight in KharkivImage caption: A Ukrainian fighter takes the automatic grenade launcher from a destroyed Russian military vehicle after the fight in Kharkiv -
President Vladimir Putin says he has ordered the Russian military to put its nuclear forces on "special alert" in response to what he described as Nato “aggression”
-
The move - which does not mean Russia intends to use the weapons - has been widely condemned, with the US calling it “totally unacceptable”, and Nato’s chief describing it as “dangerous” and “irresponsible”
-
Ukrainian and Russian delegations are set to meet on the Belarus border for talks, according to Ukraine’s President Volodymyr Zelensky
-
Ukrainian forces say they have repelled a Russian assault on the country's second city of Kharkiv
-
The number of people fleeing Ukraine has now reached 368,000, according to the latest UN figures
-
European countries are continuing to take action against Russia, with many closing their airspace to Russian flights in recent hours
Video caption: Ukraine conflict: Citizen volunteers take up arms to fight Russian invasionUkraine conflict: Citizen volunteers take up arms to fight Russian invasion ![A Russian Armoured personnel carrier (APC) burning in Kharkiv](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Getty ImagesCopyright: Getty Images A Russian armoured personnel carrier (APC) burning in KharkivImage caption: A Russian armoured personnel carrier (APC) burning in Kharkiv ![An Ukrainian Territorial Defence fighter takes the automatic grenade launcher from a destroyed Russian infantry mobility vehicle GAZ Tigr after the fight in Kharkiv](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
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Getty ImagesCopyright: Getty Images Volunteers have collected food for those who need itImage caption: Volunteers have collected food for those who need it ![Ukrainian Territorial Defence fighters patrol the streets](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
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Latest PostWorld's largest aircraft destroyed, Ukraine's foreign minister says
The world's largest aircraft - the Antonov An-225 - has been destroyed in the Russian advance, Ukraine's Foreign Minister Dmytro Kuleba says.
The plane was designed and built during the final years of the Soviet Union. It is so big the plane's cargo hold is as long as the Wright brothers’ first flight.
It was built to transport space shuttles but in recent years has rarely taken to the skies.
More protesters detained across Russia - reports
Police have detained more than 900 people protesting against the invasion Ukraine in 44 cities across Russia today, according to data released just now by an independent monitoring group.
The OVD-Info group says it brings the total number of anti-war protesters detained in Russia to over 4,000 since the conflict began four days ago.
The BBC has not been able to independently verify either figure.
Today's protests coincided with the seventh anniversary of the murder of opposition politician and Putin critic Boris Nemtsov.
Demonstrators in Moscow have been detained today at an improvised memorial near the Kremlin site where Nemtsov was shot.
One of the largest demonstration sites is in St Petersburg, where photographs show police detaining some of the several thousand protesters who have gathered in the city's centre.
Today’s biggest developments
If you’re just joining us, here’s a look back at some of today’s biggest developments:
Putin nuclear warning 'dangerous' - Nato chief
The chief of Nato says Vladimir Putin's order to the Russian military to put its nuclear forces on a higher level of alert is "dangerous" and "irresponsible".
It adds to the Russian leader's aggression over Ukraine, Jens Stoltenberg says.
"Of course when you combine this rhetoric with what they are doing on the ground in Ukraine - waging war against an independent, sovereign nation, conducting full-fledged invasion of Ukraine - this adds to the seriousness of the situation," he tells CNN.
Watch: Ukrainians take up arms to fight invasion
Video content
As the Russian invasion continues, thousands of ordinary Ukrainians are volunteering to fight to defend their neighbourhoods, despite many having no previous military experience.
Men between the ages of 18 and 60 are banned from leaving the country and have been urged to fight.
The Ukrainian defence minister says that 25,000 guns have been handed over to territorial defence members in the Kyiv region alone.
The BBC Ukrainian service visited one centre distributing weapons in the capital Kyiv.
Russia trying to apply pressure - Ukraine foreign minister
Ukrainian Foreign Minister Dmytro Kuleba has said if Russia uses nuclear weapons against Ukraine it will be a "catastrophe for the world".
"But it will not break us down," he claimed.
His comment came after Russian President Vladimir Putin ordered the Russian military to put its nuclear forces on "special alert".
Speaking at a news conference, Kuleba said: "This order by President Putin came shortly after the announcement was made about two delegations ready to meet [for talks].
"We see this announcement or this order as an attempt to raise the stakes and to put additional pressure on the Ukrainian delegation.
"But we will not give in to this pressure. We will approach these talks with a very simple approach. We go there to listen [to what] what Russia has to say and we will tell them what we think of all this."
He added: "Ukraine is not falling. We are bleeding, but we continue to successfully defend ourselves."
'At no point has Russia been under threat from Nato' - US
At no point has Russia been under threat from Nato, says White House Press Secretary Jen Psaki, in response to President Putin putting Russia's nuclear forces on "special alert".
Putin blamed Nato leaders for allowing "aggressive statements" to be made against Russia. But Psaki said it was a familiar response from Russia's president.
"We've seen him do this time and time again. At no point has Russia been under threat from Nato, has Russia been under threat from Ukraine," she told ABC News.
"This is all a pattern from President Putin and we're going to stand up to it.
"We have the ability to defend ourselves, but we also need to call out what we're seeing here from President Putin," she added.
In pictures: The aftermath of battle in Kharkiv
Ukrainian forces said they had repelled a Russian assault on the country's second city of Kharkiv.
Regional governor Oleh Synehubov said the city was now rid of Russian troops - after street-to-street fighting.
In these pictures you can see the aftermath of the fierce fighting which took place.
Nuclear warning is exactly what Nato feared
Frank Gardner
BBC Security Correspondent
Russia’s announcement that its nuclear deterrent has been put on "special alert" is a sign of both President Putin’s anger at the West’s anti-Russian sanctions and his enduring paranoia that his country is under threat from Nato.
His move has certainly got the West’s attention. This sort of escalation is exactly what Nato military planners feared and it’s why the alliance has repeatedly announced it will not be sending troops to help Ukraine repel its Russian invaders.
But Russia’s offensive is not going entirely to plan. On day four, not a single major Ukrainian city is in Russian hands and the Russians appear to be taking heavy casualties.
This will be causing some frustration and impatience in Moscow. And it’s hard to see the proposed peace talks on the Belarus border reaching a deal that works for both Moscow and Kyiv.
Putin wants Ukraine fully back into its sphere, the Zelensky government wants it to stay independent. Short of partition, that doesn’t leave much room for compromise.
So, coupled with today’s nuclear-tipped warning to the West to back off, we are likely to see an intensification of Russia’s offensive on Ukraine in coming days, with even less regard for civilian casualties than has been shown so far.
More from Kharkiv: Full statement from regional governor
As we've been reporting, Kharkiv officials say they have repelled a Russian attack, and are in charge of Ukraine's second city.
Here's a fuller translation of the statement from Kharkiv regional governor Oleh Synyehubov. The BBC has been told Kharkiv is under Ukrainian control, but we cannot verify his other claims.
"The control over Kharkiv is completely in our hands! Armed forces of Ukraine, the national police, the territorial defence forces are working: they are clearing the city of the enemy.
"The Russian enemy is completely demoralised. Right in the city, inside Kharkiv, a group of five to 10 people have surrendered to the Ukrainian army. As soon as they see at least one representative of the armed forces of Ukraine, they surrender.
"As for the situation in the wider region, here’s what is happening now: Chuhuiv [another city] is completely under control of the Ukrainian army, Ukrainian flags are hanged on the administrative buildings.
"The offensive of the Russian aggressor is ongoing in the following directions: from Lyptsi, Vovchansk, and Belhorod.
"We see separate regiments of [Russian] military vehicles. The armed forces of Ukraine are in their positions in active fighting."
RAF jets step up patrols on Russian border
Emma Vardy
Reporting from an RAF Voyager above Poland
We are in an RAF Voyager over Poland - about 50 miles from the Russian border - watching the UK’s Typhoon fighter jets refuelling in the air beside us.
British military jets have significantly stepped up their patrols since Russian forces invaded Ukraine, as part of the Nato mission to defend Europe - although the exercise is not related to President Putin's recent nuclear deterrent announcement.
The RAF Typhoons are effectively policing the skies in Poland and Romania to deter any further Russian aggression, demonstrating they have a strong presence here.
While these RAF jets are close to Russian airspace they are also able to gather information on the radar about what Russian military aircraft are in the air, and what they’re doing.
If there were to be a Russian military incursion into a Nato country, the RAF crews tell me these fighter jets would be within their rights to engage them.
But for now it’s hoped the increased presence of Nato forces in the air will send a clear message to Moscow.
Officer Mike Udall tells me: "It’s partly reassurance to show Nato allies we’re there with them, to maintain integrity of the airspace, make sure we’ve got a good understanding of who’s flying where and to react to any emerging threats.
"There’s a very human element to is and we all feel that, we all watch the news, but our role is to be there and do our own job and contribute in the way we can."
US calls Putin's nuclear move 'totally unacceptable'
The US has responded to President Putin's order putting Russia's nuclear forces on a "special" state of alert.
The move makes it easier to launch weapons - but our security correspondent Gordon Corera said it was a way for Russia to send a warning to Nato, rather than signalling an intent to use them.
The US Ambassador to the United Nations, Linda Thomas-Greenfield, called the move "unacceptable" in an interview with CBS News.
"It means that President Putin is continuing to escalate this war in a manner that is totally unacceptable and we have to continue to stem his actions in the strongest possible way," she said.
BreakingUkrainian president says delegations to meet on Belarus border
Ukrainian president Volodymyr Zelensky has released a statement following his conversation with Belarusian president Alexander Lukashenko earlier today.
“We agreed that the Ukrainian delegation would meet with the Russian delegation without preconditions on the Ukrainian-Belarusian border, near the Pripyat River," it read.
“Alexander Lukashenko has taken responsibility for ensuring that all planes, helicopters and missiles stationed on Belarusian territory remain on the ground during the Ukrainian delegation's travel, talks and return.”
Zelensky had earlier said he would not meet a Russian delegation on Belarusian territory because Russia's invasion was launched in part from Belarus.
Neither Russia nor Belarus have issued any statements about potential talks.
Russian move does not signal intent to use nuclear weapons
Gordon Corera
Security correspondent, BBC News
President Putin has ordered his military command to put nuclear forces on a "special" state of alert.
This is after what Moscow calls "aggressive statements" by Nato countries.
Russia's leader had already issued a coded warning that he was willing to use nuclear weapons as he began his invasion of Ukraine.
Last week, he warned that "whoever tries to hinder us" would see consequences "you have never seen in your history".
These words were widely interpreted as signalling a threat to use nuclear weapons if the West stood in his way.
The very public shift to high alert status is a way for Moscow to send a warning. Moving to alert status is likely to make it easier to launch weapons more quickly. But it does not mean there is a current intent to use them.
Russia has the largest stockpile of nuclear weapons in the world but also knows that Nato also has enough to destroy Russia if they were used.
But the aim is likely to try and deter Nato support for Ukraine by creating fears over how far he is willing to go and creating ambiguity over what kind of support for Ukraine he will consider to be too much.
BreakingPutin puts Russia's strategic nuclear force on 'special alert'
Russian President Vladimir Putin has ordered the Russian military to put its nuclear forces on "special alert" - the highest level of alert for Russia's Strategic Missile Forces.
Speaking to top military officials, including Defence Minister Sergei Shoigu, he said Western nations had taken "unfriendly actions" towards Russia and imposed "illegitimate sanctions".
We'll bring you an assessment of this move shortly.
'Mom, I'm scared, save me now': The view from Kharkiv
Viktoriia Zhuhan
BBC Ukrainian
Here's some more of what we're hearing from civilians on the ground in Kharkiv.
One 34-year-old woman said she spent last night in the basement of her apartment block with around 35 others.
"We were lucky last night. A blast hit the road next to our block but it didn’t hit our block," she said.
"Later, we found out that two pedestrians had been killed and another wounded. The wave of the blast was so strong that my ears popped [like when you land in a plane] even though I was sitting in the basement.
"Just before the blast our neighbour down in the basement was instructing their two young kids aged three or four what to do if there was an explosion.
"Listening to this was horrific, my hairs were standing on end at the thought that three-year-old children were having to be taught what to do during shelling.
"Throughout the night one young girl kept waking up her mum. She’d sit up crying screaming: 'Mom, I’m scared, please save me, save me now.'
"She only calmed down by the morning after her mum had sat holding her all through the night."
She said that, even though Ukrainian forces now control Kharkiv, she continues to hear blasts and that the offensive against the city appears to be ongoing.
"The reserve army volunteers are doing a great job," she said.
"I’m glued to my phone but when the connection goes down I get a little panicky, because then I don’t know how my loved ones and friends are getting on in other parts of the city.
"Every hour I look outside [above ground] to connect to the phone network and internet and call them, though it’s a risky thing to do. The tension here is horrible, but so far we are all holding on.”
Watch: Ukrainians create road blocks with sandbags
A video posted on social media appears to show defiant Ukrainians chanting and putting sand into bags to create road blocks.
"I've never seen such unity before. Everyone's loading, everyone's doing their best. Lots of bags. Glory to Ukraine,” a man can be heard saying.
The crowd responds by chanting: "Glory to heroes!" and "Glory to our nation!"
The BBC was unable to independently verify the footage, which was said to have been filmed in Kryvyi Rih - President Volodymyr Zelensky’s hometown.
100,000 at pro-Ukraine, anti-war protest in Berlin
As Germany announces a huge increase in defence spending (see below and 11:04 GMT post) German police say more than 100,000 people are taking part in a protest against the Russian invasion in Berlin.
Demonstrators have filled a large area between the Brandenburg Gate and the Victory Column / Siegessäule and more people are arriving all the time. They say the crowd could end up reaching Alexanderplatz, three kilometres away.
Earlier this week, Germany also confirmed it would be sending 1,000 anti-tank weapons and 500 Stinger missiles to Ukraine.
UK foreign secretary welcomes German plans to spend more on defence
Liz Truss reacts to the earlier news that Germany will now meet the Nato defence spend target, which is 2% of national GDP...
Kharkiv resident: 'My children are in the cellar'
Viktoriia Zhuhan
BBC Ukrainian
And here's more from the civilians we've spoken to on the ground in Kharkiv, where Ukrainian forces have repelled a Russian attack.
One university professor in his fifties said there were tanks fighting only a few kilometres from his home and that some of the street fighting was even closer.
"We are staying in our house with a cellar," he said.
"It’s my wife and me, two sons, and my 80-year-old mom. We keep the boys in the cellar most of the time.
"We have electricity, warm home, water, and connectivity.
"Not everyone is this lucky. We called our friend to join us – she has a new-born and a toddler. But she can’t take a risk to try and get to us through the whole town."
He said he's ethnically Russian and that Russian is his first language but that he is in the process of learning Ukrainian.
"I feel this is the right thing to do," he said.
"I started two or three years ago to use it at work, and recently started speaking Ukrainian in private conversations."
He added that he also believed that Ukrainian forces have regained full control of Kharkiv - as the city's governor has claimed.
"Even the groups that entered the city were killed or destroyed as far as I know," he said.
"Even when they were here, they just did a breakthrough, they didn’t control the city.”