Twenty-three people were arrested Saturday at an encampment at Indiana University, the university said.

A group erected tents and canopies on the Bloomington campus' Dunn Meadow Friday night "with the stated intention to occupy the university space indefinitely," in violation of school policy, the university said in a statement.

University and state police gave the group "multiple warnings" midday Saturday to remove the structures before detaining them for charges ranging from criminal trespass to resisting law enforcement, the university said. It is unclear what their affiliation with the university is, the school said.

"The Indiana University Police Department continues to support peaceful protests on campus that follow university policy," the university said in a statement.

The IU Divestment Coalition, a Pro-Palestinian campus group that organized the protest, said many of those arrested were students.

"They are trying to intimidate us, they are trying to break our spirit and our organizing but we will continue to stand for Gaza," the group said on social media.

Ohio State University police have arrested 36 people -- 16 of whom were students -- and charged them with criminal trespassing for encampments that remained overnight.

"Well established university rules prohibit camping and overnight events. On Thursday, April 25, demonstrators, a number of whom were not students, faculty or staff at Ohio State, exercised their First Amendment rights for several hours and were then instructed to disperse," OSU said in a statement.

"Individuals who refused to leave after multiple warnings were arrested and charged with criminal trespass. Arrests are not an action that we take lightly, and we appreciate the support of all of our law enforcement partners to disperse the encampment for the safety of our university community. We have always, and always will, take the action that is in the best interest of our community," OSU said.

Arizona State University announced that campus police have arrested 69 people for trespassing after protesters refused to leave a pro-Palestinian encampment that the university says was "unauthorized."

"Encampments are prohibited on Arizona State University property. Lawful demonstrations can take place except overnight between 11 p.m. and 5 a.m.," ASU said in a statement.

"A group of people – most of whom were not ASU students, faculty or staff – created an encampment and demonstration that continued until 11 p.m. when the group was instructed multiple times to disperse. Individuals who refused to leave after multiple warnings were arrested and charged with criminal trespass," ASU said.

Northeastern University has removed an encampment of pro-Palestinian protesters, with police detaining about 100 people. The university says students who produced valid Northeastern ID were released and will face disciplinary proceedings within the university.

"Earlier this morning the Northeastern University Police Department -- in cooperation with local law enforcement partners - began clearing an unauthorized encampment on the university's Boston campus. What began as a student demonstration two days ago was infiltrated by professional organizers with no affiliation to Northeastern. Last night, the use of virulent antisemitic slurs including "Kill the Jews," crossed the line. We cannot tolerate this kind of hate on our campus," the university said in a statement.

The university added, "As part of clearing the site, approximately 100 individuals were detained by police. Students who produced valid Northeastern ID were released. They will face disciplinary proceedings within the university, not legal action. Those who refused to disclose their affiliation were arrested."

Massachusetts State Police said they responded to Northeastern's request for assistance removing protesters.

"Officers directed protesters to disperse and MSP members assisted in removing protesters who refused to leave. Approximately 102 protesters who refused to comply with orders to disperse were arrested and will be charged by NUPD with trespassing and disorderly conduct. They are being transported to the Suffolk County House of Correction to be booked and processed," MSP said in a statement.

The White House said Sunday that President Joe Biden respects the right of demonstrators to make their voices heard -- peacefully -- and "we don't want to see anybody hurt in the process."

"The president knows that there are very strong feelings about the war in Gaza. He understands that, he respects that, and as he has said many times, we certainly respect the right of peaceful protest. People should have the ability to air their views and to share their perspectives publicly, but it has to be peaceful," White House national security spokesman John Kirby told ABC News "This Week" anchor George Stephanopoulos on Sunday.

Kirby did warn that some language heard during the demonstrations crossed a line with the administration.

"We absolutely condemn the antisemitism language that we've heard of late, and we certainly condemn all the hate speech and the threats of violence out there. These protests, we understand they're important, but they do need to be peaceful," he said.

"We'll leave it to local authorities to determine how these protests are managed," Kirby told Stephanopoulos, "but we want them to be peaceful protests and obviously we don't want to see anybody hurt in the process of peacefully protesting."

-ABC News' Tal Axelrod