Dozens of people were taken into custody during protests at Columbia University on Wednesday, and the school is once again limiting access to its campus. Only those with a university ID or approved faculty guests are allowed past checkpoints Thursday,

New York police intervened after pro-Palestinian demonstrators occupied the university’s main library Wednesday evening.

At least 40 to 50 students, their hands cuffed with plastic zip-ties, were seen being loaded into New York Police Department vans and buses.