LOS ANGELES — Pro-Palestinian protests have spread to more college campuses in the United States, as authorities appeared to be running out of patience and police began to push back forcefully.

Riot officers used chemical irritants and tasers on Thursday at one university as administrators at some of the country's most prestigious institutions battled to prevent occupations taking hold.

Staging sit-ins and mounting boisterous demonstrations, the activists are calling for a cease-fire in Israel's conflict with Hamas, as well as for colleges to sever ties with the country and with companies that they say profit from the conflict.

"For 201 days, the world has watched in silence as Israel has murdered over 30,000 Palestinians," organizers of a protest at the University of California, Los Angeles, said in an online message.

"Today, UCLA joins students across the country in demanding that our universities divest from the companies which profit off of the occupation, apartheid and genocide in Palestine."

More than 200 protesters were arrested on Wednesday and Thursday at universities in Los Angeles, Boston and Austin, Texas, where about 2,000 people gathered again on Thursday.

At Emory University in Atlanta, photographs showed police wielding tasers as they wrestled with protesters on neatly manicured lawns.

The Atlanta Police Department said officers responding to the school's request for help were "met with violence" and used "chemical irritants" in their response.

The spreading protests began at Columbia University in New York, where students dug in at their encampment for the 10th day on Friday.

The office of President Minouche Shafik issued a statement late on Thursday retreating from a midnight deadline to dismantle a large tent camp with around 200 students.

Progress in talks

"The talks have shown progress and are continuing as planned," the statement said. "We have our demands; they have theirs."

The statement denied that New York City police were invited on the campus. "This rumor is false," it said.

US ally Israel launched its offensive in Gaza after the Hamas attack on Oct 7 that killed about 1,170 people.

Hamas militants also took roughly 250 people hostage. Israel estimates 129 remain in Gaza, including 34 presumed dead.

At the University of Southern California in Los Angeles, 93 people were arrested for trespassing on Wednesday, and authorities said they were canceling events for the May 10 graduation ceremony.

The ceremony, which usually attracts 65,000 people, made headlines this month when administrators canceled a planned speech by a top student, after complaints from Jewish groups that she had links to antisemitic groups. The student denied the charge.

On Sunday, US President Joe Biden denounced "blatant antisemitism" that has "no place on college campuses".

Meanwhile, Israel has stepped up airstrikes on Rafah, killing at least six Palestinians, medics said on Thursday, after Israel said it would evacuate civilians from the Gaza border city and storm it despite allies' warnings that this could cause mass casualties.

Escalating Israeli threats to invade Rafah, the last refuge for around a million civilians who fled Israel's juggernaut further north earlier in the conflict, have nudged some families to leave for the nearby al-Mawasi coastal area or try to make their way to points further north, residents and witnesses said.

But the number of displaced people departing Rafah remained small with many confused over where they should go, saying their experience over the past 200 days of conflict had taught them that no place was genuinely safe.

Mingmei Li and Heng Weili in New York contributed to this story.

Agencies-China Daily