The University of California, Los Angeles (UCLA), one of the top public universities in the United States, cancelled all classes for Wednesday after a night of violent clashes on campus over the ongoing Israel-Hamas conflict in Gaza.

A pro-Palestinian protester kneels down in front of police officers outside an encampment of tents in support of Palestinians near Royce Hall of the University of California, Los Angeles (UCLA), in Los Angeles, California, the United States, on May 1, 2024. (Xinhua)

"Due to the distress caused by the violence that took place on Royce Quad late last night and early this morning, all classes are cancelled today," said the university in an alert to faculty, staff and students on Wednesday morning.

The university urged them to avoid the Royce Quad area and announced that Royce Hall, one of the original buildings and the defining symbol for the UCLA campus, will remain closed through Friday.

Last week, pro-Palestinian protesters set up an encampment of tents near Royce Hall in support of Palestinians.

Violent clashes erupted between pro-Palestinian protesters and pro-Israel counter-protesters late Tuesday night and lasted a couple of hours.

Fireworks, tear gas and fights broke out just after 10:50 p.m. Tuesday night local time and continued early Wednesday morning as around 100 pro-Israel counter-protesters attempted to seize the barricade around and storm the ongoing Palestine solidarity encampment, according to Daily Bruin, the university's student newspaper.

"The chaos comes as Chancellor Gene Block faces criticism for improper handling of the encampment and the same day the university deemed the encampment to be unlawful, threatening students inside with suspension and expulsion," reported Daily Bruin, adding that campus police and security retreated as pro-Israel counter-protesters and other groups attacked protesters in the encampment.

A participant in the encampment, who was granted anonymity for safety reasons, was quoted as saying by Daily Bruin that there were at least five injuries inside the encampment, most with eye injuries and some temporarily unresponsive.

Mary Osako, vice chancellor for UCLA Strategic Communications, said in a midnight statement that "horrific acts of violence occurred at the encampment tonight and we immediately called law enforcement for mutual aid support. The fire department and medical personnel are on the scene."

"We are sickened by this senseless violence and it must end," Osako noted.

Local news outlets reported that protesters clashed for more than two hours before law enforcement intervened.

Los Angeles Mayor Karen Bass said in a post on social media platform X that the violence unfolding at UCLA is "absolutely abhorrent and inexcusable."

California governor Gavin Newsom's office also said in a statement on X Tuesday night that it is closely monitoring the situation at UCLA and law enforcement leaders are in contact while "resources are being mobilized."

Following the arrest of more than 100 student protesters last month at Columbia University in New York, pro-Palestinian demonstrations are spreading at colleges and universities across the United States.

Aside from UCLA, students at some other California colleges and universities, including Stanford University, the University of Southern California, UC Berkeley, and Sacramento State, joined the national protest. A total of 35 pro-Palestinian protesters were arrested at California State Polytechnic University, Humboldt, early Tuesday morning, ending a week-long occupancy of buildings on campus of the university in Northern California.