Police in riot gear have raided Columbia University and arrested pro-Palestinian protesters occupying one of its buildings.
Around 30 to 40 people have been removed from the Manhattan university’s Hamilton Hall, according to police.
The raid came hours after New York City Mayor Eric Adams said the demonstration at the Ivy League school “must end”.
He also claimed the demonstration had been infiltrated by “professional outside agitators”.
University bosses said they called in the New York Police Department (NYPD) after protesters “chose to escalate the situation through their actions”.
“After the university learned overnight that Hamilton Hall had been occupied, vandalised, and blockaded, we were left with no choice,” a university spokesman said in a statement.
“The decision to reach out to the NYPD was in response to the actions of the protesters, not the cause they are championing.
“We have made it clear that the life of campus cannot be endlessly interrupted by protesters who violate the rules and the law.”
The protest began when students barricaded the entrance of Hamilton Hall at Columbia’s campus on Tuesday and unfurled a Palestinian flag out of a window.
Video footage showed protesters locking arms in front of the hall and carrying furniture and metal barricades to the building.
Those behind the protest said they had renamed the building “Hind’s Hall” in honour of Hind Rajab, a six-year-old girl killed in a strike on Gaza in February.
Demonstrators said they had planned to remain at the hall until the university conceded to the Columbia University Apartheid Divest’s (CUAD) three demands: divestment, financial transparency and amnesty.
However, officers moved in on the campus on Tuesday night after university bosses wrote to New York City officials and the NYPD formally asking for assistance.
A large group of officers dressed in riot gear entered the campus late on Tuesday evening. Officers were also seen entering the window of a university building via a police-branded cherry-picker-style vehicle.
Earlier, Mayor Adams urged demonstrators to leave the site. “Walk away from this situation now and continue your advocacy through other means,” he said.
Columbia University also threatened academic expulsions for students involved in the demonstration.
Protests at Columbia earlier this month kicked off demonstrations which have spread to university campuses from California to Massachusetts.
Dozens of people were arrested on Monday during protests at universities in Texas, Utah, Virginia, and New Jersey.
Police moved to clear an encampment at Yale University in Connecticut on Tuesday morning, but there were no immediate reports of arrests.
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Meanwhile, the president of the University of South California issued a statement on Tuesday after a swastika was drawn on the campus.
“I condemn any antisemitic symbols or any form of hate speech against anyone,” Carol Folt said.
“Clearly it was drawn there just to incite even more anger at a time that is so painful for our community. We’re going to work to get to the bottom of this immediately, and it has just been removed.”
Earlier, National Security Council spokesperson John Kirby said President Joe Biden believed students occupying buildings was “absolutely the wrong approach” and “not an example of peaceful protest”.