“Nazis out” was the cry from left-wing protesters in Germany on Saturday as delegates of a right-wing, anti-immigration party arrived for its annual congress.
Despite a huge police presence, hours of clashes followed in Stuttgart where demonstrators did their best to disrupt the gathering of the AfD, Alternative for Germany party.
Some 400 people were arrested.
Police said protesters threw stones at officers and attacked them with fireworks. Tear gas and pepper spray were used in response.
The clashes underline growing social tensions in Germany after a record-influx of more than 1 million migrants arrived in the country last year alone.
“We are united by our conviction that we can’t let the AfD go unchallenged and that it is a party which is not only racist but which is engaged in the politics of exclusion and social division,” said protester Dominik Schmeiser.
Police said there were more than 1,000 security forces and around the same number of demonstrators overall.
Proceedings inside the conference hall were forced to start late.
Led by Frauke Petry, the three-year-old AfD party says Islam is incompatible with Germany’s constitution.
It is expected to adopt an openly anti-Islamic manifesto this weekend.
The AfD entered three state parliaments last month by attracting votes from those opposed to Chancellor Angela Merkel’s open door policy for mainly Muslim refugees fleeing war in Syria.
The party will be encouraged by the success of the far-right in last week’s first round of presidential polls in neighbouring Austria.