ZAGREB, Croatia (AP) — The Nazi-hunting Simon Wiesenthal Center has strongly criticized a far-right singer’s participation in the celebration welcoming Croatia’s national soccer team home from the World Cup.

The center issued a statement on Wednesday that described Marko Perkovic — who goes by the stage name Thompson — as a “notorious” sympathizer of Croatia’s World War II pro-Nazi regime whose songs have advocated killing minority Serbs.

The statement says Perkovic’s prominent appearance at the festivities “gives his fascist views a legitimacy they do not deserve.”

Perkovic climbed the bus carrying the Croatian players from the airport on Monday and sang a couple of songs when he joined them on stage at a central square. He told Croatian media team members had invited him.

Nazi hunter Efraim Zuroff says Perkovic “should not be an honored guest anywhere.”