Roman Polanski, in his native Poland to pick up an award and present his new drama, “An Officer and a Spy,” canceled a lecture Saturday at his alma mater after some students and employees at the film school in Lodz took to social media and launched an online petition against his scheduled appearance.

“Like any other educational institution, our film school should be the place where sexual violence is condemned,” the petition said, noting that the filmmaker has been accused of multiple incidents of sexual misconduct. He pleaded guilty to statutory rape in California but fled the U.S. in 1978 before his sentencing.

Polanski graduated from the Lodz film school in 1959 and later received an honorary doctorate. But some opponents of his planned appearance Saturday vowed to do everything in their power to prevent him from even entering the building and pressed ahead with a protest even after Polanski canceled. A small group of young demonstrators held up banners saying “Rapist, not a Star” and clashed with some students before police ended the confrontation.

The school’s rector, Mariusz Grzegorzek, defended the decision to invite Polanski and praised the filmmaker in a lengthy statement. “Roman Polanski is a great artist of cinema, our most outstanding graduate. He has repeatedly expressed great respect for our school,” Grzegorzek said. “His achievements, and the role of the film school in Lodz in shaping his artistic path, consistently and repeatedly emphasized by the director, have become a cornerstone of our position on the international arena. We owe him a huge debt of gratitude.”

Grzegorzek added that “it is not for us to issue verdicts in matters as ambiguous and complex as allegations against Roman Polanski. So to have the community of his alma mater expressing indignation and slamming the door in his face seems to me as an extremely inappropriate act.”

Polanski was back in the headlines earlier this month after former French actor Valentine Monnier accused him of raping her at a chalet in Switzerland in 1975 when she was 18. Polanski denies the allegations and has threatened legal action against Monnier.

He was in Poland this week as the guest of the Cinergia European Cinema Forum, an eight-day festival in Lodz, which gave him a special award that honors “rebellious filmmakers going against fashion and trends.”

A few protesters at the festival’s closing gala Friday were escorted from the building by security, but the event went on uninterrupted, with Grzegorzek reiterating his support of Polanski and calling the uproar a “media-ignited frenzy” and an “embarrassment.” However, the controversy has already generated heated discussion online and in the local media, while Polanski’s star on Lodz’s walk of fame was vandalized overnight.

The film school’s student council issued a statement emphasizing the institution’s role as an “open” space for discussion. “We are not a court. It is not for us to judge Roman Polanski,” the council said. “We are concerned, however, by the media reports claiming that the ENTIRE student community is against the planned meeting with the greatest graduate of our university. We respect all of you and everyone has the right to speak. However, we do not agree with emotions dictated by hatred, which more and more often seem to be replacing substantive and rational discourse.”