Fifty-six people have been arrested at The New School and New York University after the schools authorized police to clear encampments, according to the New York Police Department.

Forty-three people were arrested at The New School and 13 people where arrested at NYU, the NYPD said.

-ABC News' Aaron Katersky

NYU has requested assistance from the NYPD to "disperse the illegal encampment on their property."

"As per their request, we are on site and our officers will be assisting with the unparalleled professionalism embodied by our police officers," NYPD Deputy Commissioner, Operations Kaz Daughtry, said in a statement on social media.

Portland police say that at least 30 people have been arrested over their involvement in ongoing protests at Portland State University.

"Additional arrests have been made at PSU’s library after trespassers illegally entered the building again despite efforts to secure it," police said in their statement. "Preliminary count is 30 arrests over the course of the day. Officers will continue to monitor for criminal activity and will make arrests when lawful and appropriate."

Authorities say that officers encountered acts of vandalism, and one suspect deployed a fire extinguisher at an officer during an altercation.

"Seven officers suffered injuries, the most serious was a knee injury that required ambulance transport to the hospital. Other injuries are still being assessed or were minor," Portland police said.

The identities of those arrested will be released once a full list has been completed.

USC has sent an email to the arrested protesters on Thursday evening warning that any student protesters who have been arrested for their "alleged conduct" of criminal trespassing on April 24 will be “referred to the University’s disciplinary process.”

"Please be aware that any further violation of university policies - including but not limited to the university's policies against camping, amplified sound, defying DPS directives, vandalism, harassments, bullying, and theft of property - will result in further discipline up to expulsion as well as an immediate ban from campus," the email obtained by ABC News said.

New York City Mayor Eric Adams urged protesters at Columbia University to "walk away" after dozens of demonstrators stormed the campus' Hamilton Hall in what he called a "violent spectacle that serves no purpose."

Adams said the peaceful demonstrations were being co-opted by "professional outside agitators" seeking to "create discord and divisiveness."

"That is why I'm urging every student, every protester to walk away from this situation now. Continue your advocacy through other means," Adams said at a press briefing Tuesday evening. "We will always protect the right to protest, but we must balance that right with the right to keep students in school and our city safe."

"We cannot wait till this situation becomes even more serious. This must end now," he added.

Chief Edward Caban reiterated that protesters who are not Columbia students are working to escalate the situation and said the New York City Police Department is ready to assist the university as needed.

"We have seen the tactics changing in a way that's endangering public safety," he said.

The NYPD showed footage of what Deputy Commissioner for Intel Rebecca Weiner said showed outside actors making barriers inside Hamilton Hall and "escalating" tactics such as scaling buildings and breaking windows. Cameras in the building have also been destroyed, Weiner said.

Individuals who occupied Hamilton Hall could face charges including burglary in the third degree, trespass and criminal mischief, police said.

A Columbia University spokesperson said Tuesday evening that dozens of protesters were in Hamilton Hall.