German police have clashed with hundreds of anti-globalisation demonstrators in the northern city of Hamburg, arresting 21 people.
Police used water cannon and baton charges against protesters, who pelted them with bottles and stones.
The violence followed a march by about 4,000 activists angered by what they saw as excessive security for a meeting of EU and Asian foreign ministers.
Germany is also tightening security ahead of next week's G8 summit.
A fence has been erected around the German Baltic Sea resort of Heiligendamm, where the summit will take place on 6-8 June. Protests will be banned from the area of the barrier.
PHOTO CAPTION
German riot police walk beside protestors as they march during a demonstrate against the upcoming G8 summit in Hamburg May 26, 2007. (Reuters)
BBC