Berlin police expressed disappointment that their attempts to prevent May Day violence, which has plagued the German capital every year for 15 years, had once again failed

Anarchists tipped over a number of cars and set them ablaze on Thursday night and threw rocks, bottles and fireworks at police and journalists. But police spokesman Karsten Graefe said a small number of assailants were to blame for the violence. "It's depressing when a small number of violent assailants ruins celebrations for everyone else," said Graefe, the chief Berlin spokesman. After years of fighting open street battles with protesters on May Day, police switched tactics last year to a more passive approach in hopes of lowering tensions and preventing violence. Police said "a good number of people" were detained and several injured people were seen being carried away from street battles between the left-wing anarchists and helmet-clad riot police. Berlin police tried to prevent any escalation and initially made no moves against demonstrations that turned violent in the Kreuzberg district. Some 2,500 riot police in the quarter stood by at first as a few stones and bottles were thrown. But authorities later fired tear gas and water cannons when the number of flung bottles and stones increased and the attackers began toppling cars and setting them on fire.