Hamburg: Police called in reinforcements from across Germany to join 20,000 officers already deployed as escalating violence marked the G20 summit.
Rallying against global capitalism, protesters played a game of cat-and-mouse with riot police, managing to stop US first lady Melania Trump attending an event with the spouses of other world leaders.
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G20: Fire in the streets as protest continue
Protesters from the radical Black Bloc movement, which wants to overthrow capitalism, continued to clash with police in Hamburg, Germany, as world leaders gathered for the G20 summit.
By midnight, Schanzenviertel, a centre of the city's left-wing activism, had become a battlefield, where about 1,500 militant protesters had set up barricades, smashed store windows and lit fires in the streets. Special forces carrying firearms were trying to clear the area, as authorities shut down some of the surrounding train stations. Police said heavily disguised protesters were attacking officers and throwing molotov cocktails.
Across Hamburg, smoke billowed from cars set ablaze.
Armoured police vehicles fanned out across the city, and helicopters patrolled. At least 196 officers - and many protesters - were reported injured since clashes began late Thursday, and about 100 protesters had been arrested, police said.
Past summits have drawn similar demonstrations. But this year's protest has targeted a triad of divisive figures: Russia's Vladimir Putin, Turkey's Recep Tayyip Erdogan and US President Donald Trump.
They are among the foreign leaders being hosted by German Chancellor Angela Merkel at a downtown conference centre and the lofty Elbphilharmonie concert hall, a crown jewel of the city, which is among the country's most affluent and yet burdened by an unemployment rate higher than the national average.
"This week is about Angela Merkel's austerity policy going global via G-20," said Jan van Aken, a member of the German Parliament from the far-left Die Linke party.
He accused the German government of seeking to suppress protest, saying its approach was autocratic and would "make Erdogan, Putin and Trump feel at home here."
The government is sensitive to this point. Merkel appealed for calm, saying on Friday that she respected "peaceful demonstrations" but considered violence "unacceptable."
"The main issue is that the summit is again, after Brisbane, in a democracy," said Wolfgang Schmidt, a Hamburg politician involved in summit planning. Summits in Turkey and China followed the 2014 meeting in Australia. "You want to make sure that protest and dissenting views are heard, but you also need to maintain security, and with 42 highly protected heads of state and finance and foreign ministers, it's a challenge."
Crowds were expected to receive a high-profile boost after New York Mayor Bill de Blasio said he would join a major rally planned for Saturday.
The discord has produced an anguished debate, unfolding on the sidelines of the summit, about security and free expression, in a port city that, for a thousand years, has connected northern Europe to the far reaches of the globe. Its trademark openness is being tested as protesters - who could number as many as 100,000 by Saturday - turned the old merchant city into a site of a global contest over capitalism and environmental degradation, among many concerns.
Tensions boiled over Thursday near Hamburg's harbour, as police tried to isolate a group of "black bloc" activists - known for their anarchist sympathies and for concealing their faces - from more than 10,000 protesters gathered for a "Welcome to Hell" demonstration.
The black bloc, which wants to overthrow capitalism, had some success in disrupting the leaders' discussions despite the ring of steel that surrounded them.
German Finance Minister Wolfgang Schaeuble cancelled an appearance in downtown Hamburg on Friday morning due to security concerns. Police also declined to clear US First Lady Melania Trump's motorcade to leave her hotel to join in a tour of the city's historic harbour, her spokeswoman said.
Thinking of those hurt in #Hamburg protests. Hope everyone stay safe! #G20
— Melania Trump (@FLOTUS) 7 July 2017
Marine police units intercepted 22 divers from the environmental pressure group Greenpeace who had also been trying to reach the concert hall, police said.
Police said they used water canon to disperse protesters who broke into a riverside metro station that had earlier been sealed off. Nearby, two lorries were set ablaze.
Three officers required treatment in hospital, police said, noting that protesters had used slingshots as well as thrown bottles and stones. At least 70 people were detained and 15 were taken into custody, police said.
In the violence, which first erupted during marches on Thursday, far-left protesters slashed the tyres of a car belonging to Canada's G20 delegation and smashed windows of Mongolia's consulate.
A police spokesman said only small numbers of far-left or anarchist protesters were involved in the disturbances, while the majority of an estimated 100,000 demonstrators in the city remained peaceful.
Left-ist traditions
Sebastian Keller, 35, said he wanted to highlight how politicians serve only economic interests, not average people.
"I'm not anti-government, but something has to change so human beings get to enjoy a little bit of the wealth," said Mr Keller, who grew up in East Germany and was eight years old when the country was reunified. "Ever since," he said, "Germany has become obsessed with capitalism."
The protests draw on a tradition of left-wing activism in Germany's second-largest city and the birthplace of its chancellor. A few kilometres away is a nerve centre of left-wing German radicalism, Rote Flora, a former theatre where activists have squatted for nearly three decades.
A spokesman for Rote Flora, Andreas Blechschmidt, promised self-defence "if the police attack us." He added: "Violence can be a productive form of protest."
Mr Erdogan's presence pits Turkish nationalists against Kurds in a country with the largest Turkish community outside Turkey. The German government has barred Mr Erdogan from addressing his supporters at the summit.
Yavuz Fersoglu, a spokesman for an umbrella organisation of Kurdish groups in Germany, said Kurds are joining hands with anti-globalisation groups for a major march on Saturday, which organisers say will draw about 100,000 people.
Local businesses were preparing for an unpredictable several days.
Richard Canning, the manager of a bar on a cobblestone street near the philharmonic that he said withstood much of the bombing during World War II, planned to close on Friday and Saturday out of concern for the safety of his staff.
He said he was sorry to lose business but happy to see Germany take on the difficult role of hosting international negotiations.
"I think that Germany is seen to be one of the major powers in Europe, and rightly so, because since the Second World War it has been building bridges, so I'm happy it's holding itself up to the world," Mr Canning said.
Washington Post, Reuters