A guest lecture by a Jewish professor on Monday at San Jose State University turned physical when police were forced to contain a rowdy crowd of protesters and protect the scholar as he exited the building, pictures and video posted on social media show.

Cal State Long Beach history Professor Jeffrey Blutinger gave a talk at SJSU billed as “exploring next steps toward peace in the Middle East” and titled “Constructing a Just Solution: Where Israelis and Palestinians Go From Here.”

According to a memo sent Tuesday by the American-Israeli Cooperative Enterprise, the event “was moved to a different location, but within 20 minutes of the lecture starting, the protests grew too large [and Bluntinger] had to stop speaking and leave via police escort for safety concerns.”