A total of 34 people were arrested while emptying a pro-Palestinian encampment at University of Wisconsin-Madison Wednesday, the university said.

The majority of those arrested have been released with no citation issued, but four people have been booked, according to the university. The charges they are facing include attempted disarming a police officer, resisting arrest, attempted escape and battery to a police officer.

Four police officers were injured at the University of Wisconsin-Madison where police were dispersing an encampment of protesters on the Library Mall.

Three of the four officers sustained injuries "directly related to the physical resistance," according to the university. A state trooper sustained injuries when a protester allegedly "struck their head with a skateboard."

Columbia University President Minouche Shafik said that tensions on campus had "rose to new heights" when a group of protesters broke into Hamilton Hall and barricaded themselves. Shafik said it pushed the university "to the brink," according to a letter sent to the Columbia University community Wednesday.

"I know I speak for many members of our community in saying that this turn of events has filled me with deep sadness. I am sorry we reached this point," Shafik said.

The NYPD said it arrested 119 people at Columbia Tuesday night, but it has not yet revealed how many of those arrested are students.

"The University offered to consider new proposals on divestment and shareholder activism, to review access to our dual degree programs and global centers, to reaffirm our commitment to free speech, and to launch educational and health programs in Gaza and the West Bank. Some other universities have achieved agreement on similar proposals. Our efforts to find a solution went into Tuesday evening, but regrettably, we were unable to come to resolution," Shafik said.

Negotiations broke down between the university and members of the encampment after Columbia refused to divest from companies linked to Israel and the war in Gaza.

The University of California, Los Angeles announced that it will cancel all Wednesday classes due to the "distress caused by the violence that took place on Royce Quad" overnight, according to a statement from the university.

The hospital and health system, the Luskin Conference Center and PreK through 12 schools will remain open.

"We have law enforcement presence stationed throughout campus to help promote safety. Student Affairs will have essential staff on campus to support our students who have been impacted by this tragedy," UCLA said in a statement.

Linda G. Mills, the president of NYU, posted a statement Friday evening explaining why the school called in the NYPD to break up an encampment on the Greene St. Walkway earlier in the day.

Mills said 14 people who refused orders to leave the area were arrested and the incident was non-violent.

The president said that the police were called in for numerous reasons, including noise complaints from nearby residents and businesses, safety concerns over the crowds of supporters and counter-protesters and escalating threats.

"The encampment had become increasingly untenable for the NYU community and the neighborhood we inhabit," she said.

Mills said three senior administrators spoke with the protesters over the weekend to come to an agreement over shutting down the encampment.

The president said things escalated on Wednesday when a group of people from a May Day march came to the walkway and got into altercations.

The May Day incident and other issues, including threats leveled at NYU administrators, led the school to call the NYPD, according to Mills.

"The university’s senior leadership and I were compelled to conclude that we could not tolerate the risk of violence any longer and that we could not responsibly or in good conscience wait until something drastically worse were to happen in order to act. We needed to bring this to a close," she said.