Three men were injured early on Sunday when a pro-democracy vigil outside the Iranian embassy in Berlin was attacked, German police said.
An officer guarding the property saw several men, whose faces were covered with scarves, tearing down flags and banners from a caravan parked outside.
They then sought to rip open the door of the caravan, and a scuffle and argument erupted between four men who were inside and the attackers.
The men from the caravan chased the other group -- and were then attacked by them, police said. Three of the men from the vehicle were injured, with two needing hospital treatment.
The attackers fled by car.
The caravan had posters on it with slogans such as "Women, Life, Freedom", which has been commonly used in anti-government protests in Iran, German media reported.
There have been large protests in Germany and other European countries in solidarity with women-led demonstrations in Iran sparked by the death in custody of Mahsa Amini.
The Iranian protests, now in their seventh week, are the biggest seen in the Islamic republic for years.