Theatergoers waiting to see the sold-out first preview of a classic Broadway musical were interrupted by neo-Nazis chanting, holding banners and passing out false information about the show’s subject. The group was identified by the musical’s producers as the National Socialist Movement, the largest membership-based neo-Nazi group in the United States, known for “violent antisemitic rhetoric and racist views,” according to the Southern Poverty Law Center.

The musical, “Parade,” first appeared on Broadway in 1998 and is being revived at the Bernard B. Jacobs Theater in midtown Manhattan. It tells the true story of Leo Frank, a Jewish factory manager who was falsely accused of murdering a 13-year-old girl named Mary Phagan in Georgia in 1913. After Frank’s sentence was commuted, he was murdered by a lynch mob. The trial, which historians believe included false testimony, and the antisemitic media coverage at the time led to the creation of the Anti-Defamation League, which still exists today.

“‘Parade’ tells an important story of what happens when antisemitism and other kinds of hatred are allowed to grow unchecked,” said Actors Equity Association, the national labor union that represents professional actors and stage managers. “…The presence of antisemitic protestor at their place of work only underlines how important that work is…We condemn the demonstration in the strongest terms.”