New York City has received authorization from Columbia University to send the NYPD onto campus, a senior city official told ABC News.

-ABC News' Aaron Katersky

University of Southern California President Carol Folt released a statement Tuesday after being alerted to an alleged swastika drawn on the USC campus.

"I've just been made aware of a swastika drawn on our campus," Folt said in an update on X Tuesday afternoon.

"I condemn any antisemitic symbols or any form of hate speech against anyone. Clearly it was drawn there to incite even more anger at a time that is so painful for our community," Folt continued.

Folt said the university is investigating and that the swastika has been removed.

Columbia University students were told to shelter in place Tuesday evening due to "heightened activity" on the Morningside campus.

"Shelter in place for your safety due to heightened activity on the Morningside campus," the university’s emergency management operations team said in an alert Tuesday.

Officials warned that "Non-compliance may result in disciplinary action" and that students should "avoid the area until further notice."

The City College of New York said it will hold classes remotely starting on Wednesday until further notice due to "current encampment activities" on the Manhattan campus.

Campus buildings will be closed except to essential personnel, the university said.

The announcement comes nearly a week after the university, which is part of the City University of New York (CUNY) system, said a group of demonstrators calling themselves the "CUNY Gaza Solidarity Encampment" set up a tent encampment on the campus' quad.

"The demonstrators appear to be made up of students, faculty and staff from City College and across the CUNY system and a sizable contingent that is not affiliated with any CUNY campus," City College President Vince Boudreau said in a letter to the community earlier this week, noting that school leaders had begun discussions with representatives from the group.

"We are working to minimize risks to people within the encampment and to protect all members of our campus community, while also minimizing the encampment's impact on campus operations," Boudreau said.

University of California President Michael V. Drake addressed the ongoing protests at UCLA that "turned violent" overnight, announcing in a statement on Wednesday an "independent external review" has been ordered.

The university summoned mutual aid from LAPD officers to "restore control" to the protest, according to Drake, who noted, there were 15 injuries, including one hospitalization, that stemmed from the protest.

"My office has requested a detailed accounting from the campus about what transpired in the early morning hours today," Drake said.

"But some confusion remains, therefore we are also ordering an independent external review of both UCLA’s planning and actions, and the effectiveness of the mutual aid response," Drake said.

UCLA's own chancellor, Gene D. Block, also promised an investigation.

"We are still gathering information about the attack on the encampment last night, and I can assure you that we will conduct a thorough investigation that may lead to arrests, expulsions and dismissals," Block told the campus community in a note Wednesday afternoon.

Block, in his note, said it was "a group of instigators" who came to Royce Quad to "forcefully attack the encampment that has been established there to advocate for Palestinian rights."

He called the overnight violence "utterly unacceptable."

"However one feels about the encampment, this attack on our students, faculty and community members was utterly unacceptable. It has shaken our campus to its core and — adding to other abhorrent incidents that we have witnessed and that have circulated on social media over the past several days — further damaged our community’s sense of security," his letter read.