Protests at U.S. universities showed no sign of slowing over the weekend, with more arrests on campuses and a brief skirmish between pro-Israeli and pro-Palestinian demonstrators at California's UCLA, where a tent encampment was set up last week.

Protesters opposed to Israel's incursion into Gaza are demanding a ceasefire in thewar with Hamas and the divestment of university assets in companies involved with the Israeli military, and an end to U.S. military assistance to Israel.

As the size of an encampment at the University of California at Los Angeles expanded in recent days, counter-protesters have become increasingly vocal and visible on the campus, although both sides remained peaceful until Sunday.

The tone turned ugly at around midday when members of two groups of protesters clashed - shoving one another and shouting, and in some cases trading punches.

Security guards attempted to keep the two sides separated, while campus police stood by and watched the brief skirmish, according to a Reuters photographer who witnessed the scene at around noon local time.

The dueling demonstrations involved at least some people from outside the university, which issued a statement on Sunday saying it had allowed two groups on campus to express their views.

Members of the Harriet Tubman Center for Social Justice planned to support the right of students to protest, according to the statement, while Stand in Support of Jewish Students, in partnership with Israeli-American Council, planned to oppose hatred and antisemitism on campus.

After the clash, the UCLA campus police department said it had dispatched more officers to the scene, and that city police were not involved. A representative of the campus police said no arrests had been made.

In the past two weeks, pro-Palestinian protests have spread to college campuses across the U.S. The proliferation was triggered by the mass arrest of over 100 people at Columbia University more than a week ago, when the school's president asked New York police to enter the campus to dismantle an encampment of tents set up by the protesters on the main lawn.

Since then, hundreds of protesters from California and Texas to Atlanta and Boston have been arrested as they emulated the encampments used by Columbia students to call attention to the humanitarian crisis in Gaza.

Administrators, including those of Columbia, have said the protests, as unauthorized, break school rules, disrupt learning and have fostered harassment and antisemitism.

The Columbia campus was peaceful on Saturday, a school spokesman told Reuters. But crackdowns took place at a handful of other campuses, including a lockdown at the University of Southern California (USC) and a heavy police presence.

More than 200 people were arrested at a handful of schools, including Washington University in St. Louis. Among those arrested at Washington University was 2024 Green Party presidential candidate Jill Stein.

"They are sending in the riot police and basically creating a riot in an otherwise peaceful demonstration. So this is just shameful," Stein said in a statement.

Washington University said in a statement that those arrested would face trespassing charges.

'STRONG FEELINGS'

The nationwide protests have caught the attention of President Joe Biden. White House national security spokesman John Kirby said on ABC News on Sunday that the president understands there were very strong feelings about the war in Gaza.

"He respects that and as he has said many times, we certainly respect the right of peaceful protest," Kirby said. "People should have the ability to air their views and to share their perspectives publicly, but it has to be peaceful."

At the same time, Kirby said, the president condemns antisemitism and condemns hate speech.

At USC, the administration last week canceled the main commencement ceremony after a decision to called off the valedictorian speech by a Muslim student, who responded by saying she was being silenced by anti-Palestinian hatred.

Los Angeles Mayor Karen Bass said on Sunday she believed that cancelling the commencement, with 65,000 people expected to attend, was a decision that USC "had to make."

"They just did not feel that it was going to be safe," Bass said on CNN's "State of the Union."

  - Reuters