More than 120 officers were injured and 86 demonstrators were detained during leftist riots in Berlin which police called "the most aggressive and violent protests in the last five years."
Police in the German capital said protesters threw bottles, cobblestones and fireworks, destroyed cars and attacked officers. Only one of the police officers required treatment at a hospital.
It was not immediately clear how many rioters were injured.
About 3,500 protesters took part in the rallies, which started on Saturday evening and lasted until early Sunday.
Activists had called for the demonstration to protest against police operations at buildings taken over by squatters in the eastern part of the city last month.
Around 1,800 police officers were called in to monitor the protesters.