Disturbances broke out in Hamburg on Monday at the tail end of a march to protest next week's G-8 summit and a meeting of EU and Asian foreign ministers, authorities said.
They said police used water cannon and batons to disperse dozens of protesters and arrested 24 people.
The march by some 4,000 anti-globalization demonstrators, according to police estimates, went relatively peacefully.
But as the march concluded, several hundred people streamed onto the city's Reeperbahn boulevard. Cars were damaged by flying beer bottles and garbage containers were thrown into the street, and stones were thrown.
Some protesters erected barricades in the street around the building of the Red Flora protest organization, which was one target of raids earlier this month against people suspected of organizing violent attacks before the Group of Eight summit.
Activists have said the pre-summit security measures are excessive. The Baltic Sea resort of Heiligendamm, site of the June 6-8 summit, has been surrounded by a fence, and protests will be banned immediately outside the barrier.
Last Mod: 29 Mayıs 2007, 13:12