Columbia University officials Tuesday were scrambling to respond to a sharp escalation in the pro-Palestinian protest, as students occupied one campus building and at least one other was vacated for student and faculty safety, according to school officials.

Students occupied Hamilton Hall early Tuesday morning, officials confirmed, after the university began suspending students who had refused to leave the encampments they've established for weeks to protest the Israeli military's actions in Gaza. Students and faculty from the university's journalism school were told to vacate Pulitzer Hall immediately and all classes would go remote, according to a university email. The university urged anyone who could, to avoid the Morningside Heights campus.

The occupation of the hall, which has been a focus of campus demonstrations for decades, followed a round of student suspensions Monday evening after weeks of protest against the Israel-Hamas war.

Suspension notices said Columbia had “already identified many students in the encampment,” and those who did not clear out before a 2 p.m. deadline would be subject to “interim suspension” pending further investigation, meaning their student IDs would be deactivated and they would lose access to all campus facilities, classrooms, housing and academic activities.

As the deadline of 2 p.m. Monday hit, protesters remained in the encampment while a group of Columbia faculty members wearing orange vests formed a line around them in solidarity. By 5:30 p.m., a statement from Ben Chang, vice president of communications at Columbia University said the university had "begun suspending students as part of this next phase of our efforts to ensure safety on our campus."

Many of the protesting students were undeterred and began occupying Hamilton Hall in the early hours of Tuesday morning.

Columbia's initial suspension ultimatum came after protesters and Columbia officials reached a stalemate in their negotiations over the protesters’ demands. And it came less than two weeks after Columbia's administration called in the NYPD to clear out an encampment on the campus' main lawn, leading to the arrests of more than 100 people.

The student protesters returned with tents days later, and the university converted all its classes to hybrid learning to the extent possible for the remainder of the academic year. Monday marks Columbia’s last day of classes before final exams begin on Friday, with commencement scheduled for May 15.

The notice of the deadline came after university President Minouche Shafik issued a statement that said Columbia officials could not reach an agreement with the protesters to clear out the encampment.

Sueda Polat, a Columbia graduate student who remained protesting in the encampment after the deadline, said she wasn't sure if she had been suspended. She took issue with the university's threat to deactivate protesters' student IDs.

“This is where we get our health care, this is where people have their dorms,” Polat, 23, said. “It essentially amounts to an eviction.”

Columbia representatives declined to comment on the notice given to protesters, and only pointed to Shafik’s statement.

Shafik said in her statement that academic leaders had been in “constructive dialogue” with student protesters since last Wednesday “to find a path forward that would result in the dismantling of the encampment and adherence to university policies going forward.” But the central demand of protesters, that Columbia pull its financial stakes out of companies tied to Israel, has been a non-starter.

Shafik said Columbia “will not divest from Israel." Such a move could be complicated, in part because Columbia and other universities do not publicly disclose all their investments.

Shafik said university leaders offered to expedite their review of other divestment proposals from student demonstrators and make it easier for students to access a list of Columbia’s "direct investment holdings."

Spokespeople for Columbia did not respond to questions about whether the negotiations with protesters would continue.

Polat said university officials “have shown a clear disregard” for the protesters’ demands.

Shafik said she had “no intention of suppressing speech or the right to peaceful protest.” University officials in recent days said they did not plan to summon the NYPD again to clear out the encampment "at this time," because it would be "counterproductive" and further inflame campus tensions.

But that was before the occupation of Hamilton Hall.

The protests have largely been peaceful, but there have been several antisemitic incidents around Columbia's campus that went viral online. Videos shared on social media two weekends ago show some protesters shouting comments like "go back to Poland" at Jewish students on the campus, which drew condemnation from the White House, Mayor Eric Adams and Gov. Kathy Hochul.

“The encampment has created an unwelcoming environment for many of our Jewish students and faculty,” Shafik said on Monday. “External actors have contributed to creating a hostile environment in violation of Title VI, especially around our gates, that is unsafe for everyone — including our neighbors."

As the encampment persists, it’s unclear how the school will move ahead with its usual commencement ceremonies. University of Southern California officials announced last week they would cancel their school's main commencement ceremony due to protests on campus.

Shafik said she wanted to “reassure our community who are trying to make plans that we will indeed hold a Commencement.” She noted that “many in this graduating class did not get a celebration when graduating from high school because of the pandemic, and many of them are the first in their families to earn a University degree.”

This story has been updated and will continue to be updated as events develop.