A Jewish man, identified in the Dutch media only as “Joram,” was verbally and physically assaulted on a national holiday known as Liberation Day, on Sunday by a group of 50 men as police stood by.

The men, wearing soccer shirts of the Feyenoord club of Rotterdam while sitting in a park near the Dutch parliament building, were singing the lyrics, “My father was in the commandos, my mother was in the SS, together they burned Jews ’cause Jews burn the best,” as Joram, 35, asked them to stop.

Despite complaints to police, they apparently did not react while the crowd pushed Joram, who was wearing a cap from Amsterdam’s Ajax team, he told the AD news site and the Center for Information and Documentation on Israel.

“Fortunately, my girlfriend and I managed to get through quite quickly,” he told the AD.

Rotterdam’s rival is Ajax, whose fans historically refer to themselves as the “Jews,” a nickname that has often led to anti-Semitic chanting by opposing fans.