New York City Mayor Eric Adams and New York Police Department officials told reporters that protesters at Columbia University were being influenced by outside individuals, part of a movement "globally" to "radicalize young people"

"Students have a right to protest and free speech is the cornerstone of our society. But as our major concern we knew and we saw that there were those who were never concerned about free speech. They were concerned about chaos. It was about external actors hijacking peaceful protests influence students to escalate," Adams said.

"You don't have to be a majority to influence and co-opt an operation," Adams said.

About 300 people were arrested at Columbia University and City College Tuesday night, New York Mayor Eric Adams said Wednesday.

"We are processing the arrests to distinguish between who were actually students and who were not supposed to be on the grounds," Adams said.

"It was led by individuals who are not affiliated with the university. The school needed the NYPD assistance to clear Hamilton Hall at the encampments outside of dual operations on the grounds that took place successfully," Adams said.

Officials said those arrested could be charged with trespassing, criminal mischef and burglary.

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NYC Mayor Eric Adams commends NYPD's handling of Columbia University protesters

Adams says there was a movement within the campus from non-students to "radicalize the situation," with 300 arrests being made.

Campus police officers at the University of Arizona in Tucson shot "chemical irritant" munitions at a gathering of protesters early Wednesday, the department said.

The university's president, Robert C. Robbins, had asked the campus police and school officials to "immediately enforce campus use policies and all corresponding laws," according to a statement from his office.

The Tucson Police Department and other law enforcement agencies also responded to campus, the university said.

Campus officers closed several blocks of Park Avenue as they responded to the "unlawful assembly," the department said.

Video appeared to show police handcuffing individuals on the ground and protesters forming a human chain facing officers.

"Police deploying chemical irritant munitions," the department said amid a series of updates on social media. "Follow orders of police and disperse immediately. Avoid the area of University Blvd & Park Ave."

-ABC News' Amanda Morris and Kevin Shalvey

As groups of counter-protesters clashed with Pro-Palestinian demonstrators on the UCLA campus early Wednesday, a university official said staff were “sickened” by the violence.

“Horrific acts of violence occurred at the encampment tonight and we immediately called law enforcement for mutual aid support,” Mary Osaka, a vice chancellor, said in a statement.

Osaka aded that the fire department and medical responders were near the scene.

"We are sickened by this senseless violence and it must end,” she said.

-ABC News’ Bonnie Mclean and Kevin Shalvey