German police say at least 22 officers have been injured and dozens of people detained during unrest at an Eritrean cultural event in the western city of Giessen.
Police said bottles were thrown and smoke bombs were ignited as groups of Eritreans opposed to the African nation's autocratic ruler tried to force their way to the venue on Saturday.
About 1,000 officers, a water cannon and helicopters were deployed in the city, which is about 50 kilometres north of Frankfurt.
Police spokesperson Christopher Pfaff urged the public to avoid the centre of Giessen while the operation is ongoing.
Failed ban attempts
Authorities had tried to ban the festival after similar unrest occurred there last year, but a court overturned the order.
The event was organised by a group considered close to the government of Eritrean President Isaias Afwerki.
Tens of thousands of people have fled Eritrea for Europe, many alleging they were mistreated by Afwerki's government.
