Clashes between 4,000 far-left demonstrators and the police left 10 officers injured in the German city of Hamburg on Saturday on the eve of traditional May Day celebrations, police said.
“A car and waste containers were set on fire. Demonstrators threw stones and paint bombs at the police which used water cannon” to disperse the crowd, said a Hamburg police spokesman.
In the capital Berlin some 3,000 police were deployed late Saturday and there would be twice as many the following night, a police spokesman told AFP.
In Hamburg, Germany’s second largest city and biggest port, 2,500 officers policed the demonstrations.
Officers from other regions have been called in as reinforcements to both cities.
“I think we will see new clashes,” DPolG police union official Bodo Pfalzgraf told rbb radio and television in Berlin.
May 1, the international day of the worker, has for the past two decades been accompanied in German cities by sporadic street violence and pitched battles between far-right skinheads, anti-fascist groups and police.
After several relatively peaceful years, clashes returned to the capital in 2009.
Last year eight police officers and a fireman were injured in clashes in Berlin’s central Kreuzberg district as demonstrators torched cars and waste containers.
In Hamburg, five policemen and a firefighter were also hurt in the violence.