Anti-Israel demonstrators have stormed and seized an academic building at Columbia University in New York, in the latest escalation of the protest movement against Israel’s war in Gaza that has unfolded across US college campuses.

According to multiple videos posted online and local media reports, dozens of protesters crowded outside Hamilton Hall on Columbia’s Manhattan campus early on Tuesday. They then started smashing windows and broke into the building. The hall is known for having been similarly occupied during a 1968 civil rights and anti-Vietnam war protest at the university.

The protesters have since barricaded the entrances to the hall and unfurled a Palestinian flag out of one of its windows, as well as banner renaming the building ‘Hind’s Hall,’ after Hind Rajab, a six-year-old Palestinian killed in Gaza three months ago.

Some protesters later formed a human chain outside the building.

Columbia confirmed the occupation of Hamilton Hall and warned students by email to stay away from campus on Tuesday.

The protests at Columbia had previously largely been limited to an encampment on the university’s main lawn. However, the school ordered the activists to dismantle the encampment, and started suspending those involved after a deadline to abandon the makeshift camp expired at 2pm local time on Monday.