Columbia students reported feeling threatened when masked protesters stormed the campus library, chanted anti-Israel slogans, and mocked the Israeli hostage crisis.

Pro-Palestinian protesters took over the main library at Columbia University, hanging Palestinian flags from the walls, the first major demonstration on the campus since the ones that overwhelmed the school last spring.

Columbia University has suspended dozens of students and barred alums and others who participated in a pro-Palestinian demonstration inside the school’s main library earlier this week