Police cleared out an encampment at Virginia Tech late Sunday after protesters had set up tents on the lawn of the campus' Graduate Life Center.

"Those who gathered were advised by university officials to remove their possessions and to disperse voluntarily; those who failed to comply were then approached by Virginia Tech Police and were again asked to leave and advised that anyone who failed to comply would be charged with trespassing, in accordance with Virginia law," the school said in a statement.

The university added, "At approximately 10:15 p.m., police approached protesters to ask them to disperse within five minutes. Those who remained were subject to arrest."

Dozens of protesters were taken into custody, according to Lynchburg, Virginia, ABC affiliate WSET.

UCLA announced it is instituting additional security measures amid protests on campus over the Israel-Hamas war in a statement on Sunday.

"UCLA has a long history of peaceful protest and we are heartbroken to report that today, some physical altercations broke out among demonstrators on Royce Quad," Mary Osako, vice chancellor of UCLA Strategic Communications said.

"We have since instituted additional security measures and increased the numbers of our safety team members on site," Osako said.

"As an institution of higher education, we stand firmly for the idea that even when we disagree, we must still engage respectfully and recognize one another’s humanity," Osako continued.

Addressing the physical altercations during the protests, Osako said, "We are dismayed that certain individuals instead chose to jeopardize the physical safety of the community."

Last week, the University of California rejected calls to divest from companies that do business with Israel.

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

The University of Southern California closed its main campus Saturday evening "due to a disturbance," the university said on X.

Los Angeles Police Department issued a citywide tactical alert due to a protest on USC's campus, urging people to avoid the area.

A tactical alert allows LAPD to keep officers on past their shifts and to move officers between divisions if they need extra staffing in one area of the city.

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.