A pro-Palestinian encampment on the campus of the University of Southern California was being cleared Sunday morning as campus police warned protesters to leave or be arrested.

The announcement came as the USC Department of Public Safety closed the campus "as a result of significant activity at the center of campus."

"If you are in the center of campus, please leave. People who don’t leave will be arrested. We will issue another alert when it is clear to return," the DPS said on X.

The campus police said officers from the Los Angeles Police Department are assisting in "clearing the center" of the University Park Campus.

Sunday's action came after USC President Carol Folt sent an email to the school's community, saying "steps would be taken to ensure a quiet and safe environment for students to complete their finals."

“[L]et me be absolutely clear: free speech and assembly do not include the right to obstruct equal access to campus, damage property, or foment harassment, violence, and threats,” Folt said. “Nor is anyone entitled to obstruct the normal functions of our university, including commencement."

-ABC News' Cory Peeler

Authorities arrested 25 protesters at the University of Virginia for trespassing on Saturday, according to the university's communications office.

The school said it was still awaiting confirmation on how many of those arrested were affiliated with UVA.

Approximately 50 people were arrested, including some students, at The Art Institute of Chicago on Saturday, according to a spokesperson from the museum.

"Today, a group of individuals, including some SAIC students, began a protest in the museum’s North Garden, and as it progressed, protesters surrounded and shoved a security officer and stole their keys to the museum, blocked emergency exits, and barricaded gates," the statement read.

Protesters were offered an alternative location to continue the protest on campus, but they did not accept that offer, according to the spokesperson.

"During multiple rounds of negotiations, SAIC student protesters were promised amnesty from academic sanction and trespassing charges if they agreed to relocate. The School also agreed to meet with a student group to discuss their demands. After approximately five hours, an agreement could not be reached."

Chicago Police Department assisted with ending the protests and arresting individuals, the museum spokesperson said.

The president of the University of Virginia, Jim Ryan, released a statement Saturday on the removal of protesters from the encampment on campus.

Ryan said that up until Friday, the demonstrations on campus had remained peaceful and "complied with requests to adhere to University policies including a long-standing prohibition on erecting tents absent a permit."

However, Ryan said protesters were given a "final warning" on Saturday morning that "was ignored" and the university’s police department officers "were met with physical confrontation and attempted assault."

Virginia State Police were called to clear the encampment after it was deemed an "unlawful" assembly, according to the president.

"I recognize and respect that some will disagree with our decisions,” Ryan said in the statement. “This entire episode was upsetting, frightening and sad."

Over 300 Harvard University professors have signed a letter to the university urging "constructive dialogue" with the peaceful protesters on campus.

"We are concerned that the university has yet to meet with the students to hear their concerns. Instead, the administration has issued escalating threats of punitive disciplinary action, the severity of which the university has not seen in decades," professors wrote.

"We urge the administration to meet and engage in meaningful dialogue with peacefully protesting students," the letter said.

The letter, sent to interim President Alan Garber and interim Provost John F. Manning Tuesday, came after Harvard warned protesters to empty their encampment. The professors are urging Harvard's administration to follow the lead of Brown University and Northwestern University, where encampments ended after school leadership agreed to take steps toward divestment.

"I think so many of us signed this letter because, as faculty, we have a duty of care towards our students. The harshness and scale of the proposed punishment is unprecedented and frankly alarming; these are activities that should be met with dialogue, not punishment," Teju Cole, a Gore Vidal professor of the practice of creative writing at Harvard, said in a statement.

"We are calling on the administration to be fair-minded and set these protests in the context of numerous other protests that have happened here in the past, in response to which the university did the right thing," Cole said.