Thirty-two of the people arrested at Columbia University on Tuesday were not affiliated with the school, while 80 people were affiliated, based on a preliminary background analysis by the New York Police Department.

At City College of New York, 102 people arrested Tuesday night were not affiliated with the university, while 68 people were affiliated, based on the NYPD analysis.

-ABC News' Aaron Katersky

The University of Minnesota has reached an agreement to end the student-led encampment on campus.

The university will reopen previously closed buildings and the student coalition has pledged not to organize disruptions during final exams and the commencement ceremony.

Representatives of the student coalition will be given the opportunity to address the Board of Regents at its May 10 meeting over its call for a divestment, students will receive amnesty for their encampment, and the university will also explore an affiliation with Palestinian universities, hosting scholars at risk.

"Our meetings have been grounded in listening, learning, and respect, and I believe they were a very positive first step in reaching mutual understanding. Though the original meeting was scheduled for 30 minutes yesterday, we engaged in constructive conversation for more than 90 minutes. We then met two more times to discuss the proposed agreements," University of Minnesota interim President Jeff Ettinger said in a statement.

"We regret that these meetings did not happen sooner, and have committed to regular meetings moving forward to continue to discuss this coalition’s concerns," Ettinger said.

Ettinger also highlighted that the university supports freedom of expression as a fundamental part of its mission.

"While we do not condone tactics that are outside of our policies, we appreciate student leaders’ willingness to engage in dialogue. I value the challenging and healthy conversations we’ve had," Ettinger said.

Officers began arresting protesters on the University of California Los Angeles campus early Thursday, detaining some with their hands zip-tied behind their backs.

Those who were detained appeared to have been moving willingly with officers, ABC News station KABC reported.

As law enforcement moved into the encampment, some of the protesters began chanting, repeating the phrase "Shame on you" in chorus.

-ABC News' Jenna Harrison and Kevin Shalvey

UCLA officials issued an evacuation order for all protesters in the area of Royce Quad, saying the encampment was "unlawful."

Smoke billowed around law enforcement officials as they began breaking through the barricades on the campus encampment. It was not immediately clear whether the smoke had been dispersed by the police or the protesters.

The encampment in Dickson Plaza, along with all unauthorized tents and structures, had been declared "unlawful," campus public safety officials said in an alert.

"The University requires that everyone must leave the encampment and adjacent areas, as well as all unauthorized structures and tents immediately, until further notice," the alert said.

-ABC News’ Amanda Morris and Kevin Shalvey

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.