Clashing groups of competing protesters overnight at the University of California, Los Angeles, fought, kicked, and struck each other with sticks after pro-Israel demonstrators attempted to remove barriers surrounding a Palestinian-supporting camp. Hours earlier, police stormed the building occupied by anti-war protesters at Columbia University to disperse a demonstration that had paralyzed the campus.

After several hours of skirmishes among protesters at the University of California, police wearing helmets and armor slowly separated the groups and quelled the violence. The scene was calm with the dawn.

The University of California, Los Angeles canceled classes on Wednesday and urged people to avoid the area where the fighting broke out. The university library will not open until Monday, and Royce Hall, which authorities said had been vandalized, will remain closed until Friday. The University of California deployed law enforcement officers throughout the campus.

Tents of protesters demanding universities stop commercial dealings with Israel or companies supporting the war in Gaza spread across campuses nationwide in an unparalleled student movement this century. Police crackdowns reminiscent of those that occurred decades ago against a much larger anti-Vietnam War protest movement were repeated.

Confrontations with law enforcement occurred, resulting in the arrest of more than 1,000 people. In rare instances, university officials and protest leaders reached agreements to limit disruptions to campus life and upcoming graduation ceremonies.

Clashes broke out at the University of California, Los Angeles when opposing demonstrators attempted to dismantle barriers of display, plywood, and wooden platforms protecting a camp built by pro-Palestinian protesters. Video footage showed fireworks exploding above and inside the camp.

People threw chairs and other objects. A group piled on top of a person lying on the ground, kicking and striking him with sticks until others pulled him from the crowd.

People outside the camp, one wrapped in an Israeli flag, played recordings of various sounds, including a baby crying and alarm sirens.

Authorities did not provide details about injuries.

For her part, Los Angeles Mayor Karen Bass called the violence "completely vile and uncalled for" in a social media post, stating that the city police were on the scene. California Highway Patrol officers also appeared to have joined. The university stated that it had requested assistance.

The university heightened security measures on Tuesday after officials reported "physical altercations."

Late Tuesday, NYPD officers entered the Columbia University campus after the university requested help. They dismantled the camp, alongside Hamilton Hall, where a group of officers used a ladder to climb through a second-floor window, as demonstrators had seized the Ivy League building about 20 hours earlier.

The university stated: "After learning overnight that Hamilton Hall had been occupied, vandalized, and blockaded, we had no choice."

A few dozen protesters were arrested at Columbia after ignoring an earlier warning to leave the camp on Monday or face suspension, inspiring demonstrations at universities elsewhere.

Fabian Lugo, a first-year accounting student who said he did not participate in the protests, opposed the university’s decision to call the police.

He added, "This is extremely intense." "It feels like an escalation more than a de-escalation."

Just buildings away from Columbia, at City College of New York, protesters faced off with police outside the main gate of the public college. Video footage shared by journalists on social media late Tuesday showed officers forcing some individuals to the ground and pushing others as they cleared the street and sidewalks.

After police arrived, officers removed the Palestinian flag from a flagpole at City College and threw it on the ground before raising the American flag.

Brown University, another Ivy League school, reached an agreement on Tuesday with protesters on its Rhode Island campus. The protesters said they would dismantle their camp if officials considered divesting from Israel in October—apparently the first time an American college has agreed to protesters’ demands for a vote on divestment.

Meanwhile, at Northern Arizona University in Flagstaff, riot police shut down one of the camps late Tuesday and arrested about 20 people for trespassing, with university officials warning that students would face criminal charges if they did not disperse.

First-year student Braden Lang watched from the sidelines.

He said, "I still know very little about this conflict," "but the death of thousands is something I cannot bear."

The police also cleared a camp Wednesday morning at Tulane University in New Orleans and removed all tents except one at the University of Wisconsin Madison, where officers pushed protesters with batons, leading to a mass of people and at least a dozen arrests. Four officers were injured, including a state trooper hit in the head with a skateboard, according to Wisconsin University Police spokesperson Mark Lofquist.

Humboldt State University was assessing damage after police cleared demonstrators from two halls they had occupied since early last week. The university said in a statement that those arrested included 13 students and a faculty member, along with 18 non-students.

Protests erupted across the Columbia University campus in response to the Israeli assault on Gaza after Hamas launched a deadly attack on southern Israel on October 7. Militants killed about 1,200 people, mostly civilians, and took almost 250 hostages, with Israel vowing to eradicate Hamas, killing over 34,000 Palestinians in Gaza, according to the health ministry there.

While ceasefire negotiations appear to be gaining momentum, it was unclear whether those discussions would lead to a de-escalation of protests.

Israel and its supporters have described the campus protests as anti-Semitic, while critics of Israel say it uses these claims to silence opposition. While some protesters have been filmed making anti-Semitic statements or violent threats, organizers of the protests, some of whom are Jewish, say it is a peaceful movement aimed at defending Palestinian rights and protesting the war.

The police action at Columbia comes on the 56th anniversary of a similar crackdown on student protests against racism and the Vietnam War in Hamilton Hall.

The police department stated that officers would not enter without a request from the college administration or in the event of an imminent emergency. Now, law enforcement will be present until May 17, the scheduled end date of the university's graduation events.

In a message to senior police officials, Columbia President Nemat Shafik, who goes by the first name Minouche, said the administration requested that officers remove protesters from the occupied building and encampment "with deep regret."

New York City Mayor Eric Adams, a Democrat and former police captain, insisted that while students were among those who entered Hamilton Hall, "it was led by individuals not affiliated with the university."

Adams provided no evidence to support this claim, stating that disclosing these details would be "extremely sensitive" to an ongoing law enforcement investigation.

Rebecca Weiner, Deputy Commissioner for Intelligence and Counterterrorism at NYPD, said that some protesters are "known" to the department for having participated in previous demonstrations.

Tarik Shepherd, Deputy Commissioner of Police for Media Relations, stated that between 40 and 50 people were arrested in Hamilton Hall, with no injuries reported. Adams said nearly 300 people were arrested at Columbia University and City College in police crackdowns.

Protesters first set up camp at Columbia about two weeks ago. The university sent police to clear the tents the following day, arresting more than 100 people, only for students to return.

Negotiations between protesters and the college had stalled in recent days, with the university setting a deadline for activists to leave the camp by Monday afternoon or face suspension.

Instead, the protesters seized Hamilton Hall early Tuesday, carrying furniture and metal barriers.