The Libyan government has called an immediate ceasefire in the face of the imminent threat of international military intervention, after a no-fly zone was authorised by a UN security council resolution.
Despite the declaration, attacks on opposition-held territory continued and the revolutionary council rejected the ceasefire.
The US secretary of state, Hillary Clinton, demanded "action on the ground" and not just words.
Before the Libyan announcement, David Cameron said aircraft were being moved to bases "in the coming hours … to take the necessary action" and a French government spokesman said air strikes could be launched within hours.
Libya rapidly responded, with the foreign minister, Mussa Qusa, announcing: "Libya has decided [on] an immediate ceasefire and stoppage of all military operations."
Qusa said the action taken by the security council was "a violation of the national sovereignty of Libya". By contrast, he made a renewed appeal for dialogue with opponents within the country "interested in the territorial integrity of Libya".
But even after his statement, the bombardment of opposition forces continued. Civilian buildings, including a mosque, reportedly came under fire from tanks and artillery in Misrata, the last rebel stronghold in the west of the country. A doctor told Reuters at least 25 people were killed in the city.
Al-Jazeera reported that Gaddafi's troops had struck the Rajban and Zintan areas in the western mountains, and that there were clashes in the eastern city of Ajdabiya.
Mustafa Gheriani, a spokesman for the national opposition council based in Benghazi, said Gaddafi forces were still attacking across the country and there could be "no ceasefire".
Clinton said the regime had to do more to convince the world it was not going to resort to further military force. "We are going to be not responsive or impressed by words, we would have to see actions on the ground and that is not yet at all clear. We will continue to work with our partners in the international community to press Gaddafi to leave and to support the legitimate aspirations of the Libyan people."
The ceasefire declaration came hours after Saif al-Islam, the son of Muammar Gaddafi, laughed off the idea that the regime was afraid of the international community, telling al-Arabiya TV that government forces would encircle Benghazi, home to the revolutionary council.
Gaddafi himself had called the vote "flagrant colonisation" and warned of dire consequences. "This is craziness, madness, arrogance," he told the Portuguese TV channel RTP. "If the world gets crazy with us, we will get crazy too. We will respond."
After the 15-member security council voted on Thursday night in favour of a resolution authorising all necessary measures to protect Libyan civilians under threat of attack, in particular in Benghazi, countries moved swiftly to declare their willingness to help implement it.
As well as France and the UK, which together drafted the resolution, Norway said it would take part in military intervention, while Denmark said it was planning to send seven aircraft – six F16s and one transport carrier – to be stationed at bases in southern Europe in preparation for any action. Belgium said it would send six F16s and a frigate.
Before Qusa had spoken, the French government spokesman François Baroin said military intervention against Gaddafi's regime would happen "rapidly … in a few hours" but did not give details of what the action would involve. He said the action would allow the Libyan people "to achieve their aim of liberty and therefore the fall of the Gaddafi regime".
Television pictures showed the opposition in Benghazi celebrating after Qusa announced the Libyan government's concessions, just as they had after the UN resolution was passed.
Ten members of the security council voted in favour, with five abstaining, including China, Russia and Germany. The US backed the resolution, a complete turnaround after weeks of resisting no-fly zone proposals, but did not say what role it would play and cautioned against immediate action.
