A small group of protesters demonstrated inside a building at Barnard College’s campus in Manhattan Wednesday in support of two students who were reportedly expelled for disrupting an Israeli history class last month, according to student activists and Barnard officials.

Nearly 100 students from Barnard and Columbia University—which is affiliated with Barnard and was a focal point of pro-Palestinian demonstrations last year—staged a sit-in at Barnard’s Milbank Hall, the activist group Columbia University Apartheid Divest, or CUAD, said on social media.

Videos posted to social media by CUAD Wednesday showed masked students, many of them wearing keffiyehs, a traditional Middle Eastern scarf often symbolizing Palestinian identity, sitting inside a hallway chanting, clapping, and beating drums.

A Barnard spokesperson told CNN the students “physically assaulted a Barnard employee, sending them to the hospital.”

CUAD said on social media Barnard security staff “harassed and shoved several students, knocking at least one to the ground.” CNN has reached out to the group for comment.

By Wednesday evening, the protesters had left Milbank Hall without further incident after Barnard set a deadline and warned of further action.

“Let us be clear: their disregard for the safety of our community remains completely unacceptable,” Barnard President Laura Rosenbury said in a statement.

The expulsions of the Barnard students were disclosed by CUAD on Saturday. Barnard declined to discuss the status of the students involved, citing federal law and privacy concerns.

Wednesday’s sit-in was part of a week of action organized by CUAD to protest the expulsions in connection with their suspected involvement in disrupting a history class at Columbia last month.

On January 21, several individuals disrupted the first day of a History of Modern Israel class by handing out flyers with what the university called “violent imagery.”

In a statement to CNN, Rosenbury said the college cannot comment on individual students’ records, but “as a matter of principle and policy, Barnard will always take decisive action to protect our community as a place where learning thrives, individuals feel safe, and higher education is celebrated.”

“When rules are broken, when there is no remorse, no reflection, and no willingness to change, we must act,” Rosenbury said. “Expulsion is always an extraordinary measure, but so too is our commitment to respect, inclusion, and the integrity of the academic experience.”

Barnard spokesperson Robin Levine told CNN in a statement Wednesday its leadership “made multiple good-faith efforts to de-escalate” the demonstration and “offered to meet with the protesters—just as we meet with all members of our community—on one simple condition: remove their masks. They refused. We have also offered mediation.”

Among the protesters’ demands are the reversal of the expulsions, amnesty for students disciplined for “pro-Palestine action or thought,” a public meeting with Rosenbury and Barnard Dean Leslie Grinage, and full transparency in disciplinary proceedings, according to CUAD.

The group is also planning a mass picket outside Barnard gates on Thursday in support of the expelled students.

Wednesday’s protest at Barnard follows a years-long spate of high-profile incidents at universities across the country in response to the Israel-Hamas war in Gaza, of which Columbia has been a focal point.

Last year at Columbia was marked by protests, an encampment on school grounds, a building occupation, and the mass arrest of more than 100 demonstrators. The university’s president resigned in August amid mounting pressure over Columbia’s handling of the protests.

In April, Barnard suspended at least 55 students for their alleged participation in pro-Palestinian encampments at Columbia, the Spectator reported.

Columbia said in a statement on its website that the protests on Wednesday are not taking place on its campus and Barnard’s leadership and security team are assessing the situation.

“The disruption of academic activities is not acceptable conduct,” the statement said. “We are committed to supporting our Columbia student body and our campus community during this challenging time.”