Violent clashes erupted on the campus of the University of California in Los Angeles (UCLA) between pro-Palestinian protesters and a group of counter-demonstrators supporting Israel.
According to the UCLA student newspaper Daily Bruin, police were deployed to the campus after the Israel supporters tried to tear down a pro-Palestinian protest encampment.
The student protests in the US have also taken on political overtones in the run-up to the presidential election in November.
Republicans have accused some university administrators of turning a blind eye to antisemitic rhetoric and harassment.
Los Angeles Councilwoman Katy Yaroslavsky, whose district includes UCLA, posted on social media: "Everyone has a right to free speech and protest, but the situation on UCLA’s campus is out of control and is no longer safe."
The Los Angeles Police Department said on X, formerly Twitter, it was responding to UCLA's request "due to multiple acts of violence within the large encampment on their campus", to restore order and maintain public safety.
Footage from broadcaster KABC, an ABC affiliate, showed people wielding sticks or poles to attack wooden boards being held up as a makeshift barricade to protect pro-Palestinian protesters, some of whom held placards or umbrellas.
The October 7 attacks on Israel by Hamas fighters has led to the biggest demonstration of US student activism since the anti-racism protests of 2020.
On Tuesday night, New York City police arrested dozens of pro-Palestinian demonstrators holed up in a building at Columbia University and removed a protest encampment that the Ivy League school had sought to dismantle for nearly two weeks.
Officers climbed into Hamilton Hall in New York through a second-storey window. Within three hours, they had cleared the protesters and arrested dozens, a police spokesperson said.
Columbia President Minouche Shafik released a letter asking police to stay on campus until at least May 17 - two days after graduation - "to maintain order and ensure that encampments are not re-established".
Students standing outside the hall - the site of various student occupations dating back to the 1960s - jeered at police with shouts of "Shame, shame!".
Supporters of Israel erected a screen that played a video loop of scenes from the Hamas October 7 attack.
The two sides taunted one another, pushed, shoved and threw punches while campus police struggled to contain the skirmishes.
