Video posted on social media showed chanting protesters entering the library, many wearing keffiyeh headscarves and masks, defying a ban imposed by the Trump administration.
More than 70 protesters were arrested by the police, Columbia Spectator, a campus newspaper, reported. In a post on social media, the protestors accused the university of “violent repression”.
It marks the first time that Columbia University has called the NYPD for an on-campus protest since April 2024, when pro-Palestinian protesters occupied Hamilton Hall for nearly 24 hours.
The New York college was the epicentre of pro-Palestinian protests against the war in Gaza and US support for Israel on college campuses last year.
In March, Columbia agreed to several demands from the Trump administration, including a ban on face masks at protests and a change in oversight of some academic programmes, after the administration said it planned to withhold millions in federal funds.
