Poland has decided to expel 63 people, mostly Ukrainians, after violence at a concert in Warsaw sparked controversy over historical symbols.

Prime Minister Donald Tusk has announced the expulsion of 63 people following violence at a concert in Warsaw, where attendees clashed with security guards. The incident caused tensions in Polish-Ukrainian relations, in particular because of the presence of a flag associated with the Ukrainian Insurrectionary Army (UPA), controversial in Poland because of historic massacres. Police detained more than 100 people for assault and other offenses, and Tusk emphasized that expulsion proceedings have been initiated.