The German government condemned on Monday the violent clashes occurred during the weekend at a controversial Eritrean music festival held in the town of Giessen, north of Frankfurt.
At least 26 police officers were injured and around 130 arrests were made.
Opponents of the festival accuse the organisers of being close to the authoritarian regime in Eritrea, and of using the event, which has been running since 2011, as "propaganda" for the ruling power.
Local elected representatives called on Olaf Scholz's government to summon Eritrean representatives to the country.
Eritrea officially became a state in May 1993, two years after throwing off Ethiopian domination.
Since then, the country has been ruled by independence hero Issaias Afeworki, who has established a one-party regime without elections, where any opposition is severely repressed.