Four Christians have been beaten up in Berlin, Germany’s capital city, in the early hours of Saturday morning.

German media reports that four men were leaving the Adagio venue in the bustling Potzdamer Platz area when they were challenged by a man who exclaimed: “I am a Muslim! What are you?” before setting upon the four 20-somethings. He was reportedly assisted by four, older accomplices.

Police are now investigating the incident as a politically motivated attack, and at least five people are thought to have been injured in the melee, including one passer by who tried to settle the dispute.

The injured apparently refused medical treatment, and police records indicated they were from Serbia and Montenegro, and are Orthodox Christians.

According to the Tagespiegel newspaper, the venue in the heart of Berlin was hosting a “Balkan Party” in the evening on Christmas Day.

The assailants fled the scene before police arrived, and there have been no reports yet as to their whereabouts.