Violent clashes have broken out in Germany’s financial capital during anti-capitalist protests marking the opening of the European Central Bank’s new headquarters.
Police in Frankfurt say they have so far detained 550 demonstrators after trouble flared on Wednesday, which saw water cannon used.
More than 90 officers were reportedly injured after police and firefighters came under attack from activists throwing stones and tear gas.
Rally organisers said more than 100 protesters were hurt by police.
A number of cars were also torched across the city, including seven police patrol vehicles.
Streets were closed by stacks of burning tyres and rubbish bins, while shops were also damaged.
The police and fire departments both issued appeals on Twitter, urging protesters to remain calm.
“Our firefighters are being attacked. Please stop doing that!” Frankfurt Fire Department tweeted.
Shortly before the ECB building’s inauguration, police used water cannon to disperse groups of protesters gathered outside the security zone around the 185-metre (605ft) new skyscraper.
Later, police said 17,000 people, under the “Blockupy” banner, took part in a procession across the city where there was a major police presence.
“It is one of the biggest deployments ever in the city,” a police spokeswoman told news agency AFP.
The authorities said stones had been thrown at officers and warned water cannon was on standby.
German leaders condemned the violence but defended people’s right to protest.
Finance Minister Wolfgang Schaeuble said: “No one has the right to endanger the life of police and fire officials.”