Ninety-three people were arrested at the University of Southern California's Los Angeles campus after pro-Palestinian protests erupted across US universities AFP

Columbia University backed off late Thursday from an overnight deadline for pro-Palestinian protesters to abandon an encampment there as more college campuses in the United States sought to prevent occupations from taking hold.

Police have carried out large-scale arrests in universities across the country, at times using chemical irritants and tasers to disperse protests over Israel's war with Hamas.

The office of New York-based Columbia University president Minouche Shafik issued a statement at 11:07 pm (0307 GMT Friday) retreating from a midnight deadline to dismantle a large tent camp with around 200 students.

"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.

A student, identifying herself only as Mimi, told AFP she had been at the camp for seven days.

"They call us terrorists, they call us violent. But... they're the ones that called in the police when students were sitting in a circle," she said.

"The police are the ones with guns, the police are the ones with tasers, we only have our voices."

Student protesters say they are expressing solidarity with Palestinians in Gaza, where the death toll has topped 34,305, according to the Hamas-run territory's health ministry.

More than 200 people protesting the war were arrested Wednesday and early Thursday at universities in Los Angeles, Boston and Austin, Texas, where around 2,000 people gathered again on Thursday.

Riot officers in the southern state of Georgia used chemical irritants and tasers to disperse protests 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, which has remained the epicenter of the student protest movement.

The protests pose a major challenge to university administrators who are trying to balance campus commitments to free expression with complaints that the rallies have crossed a line.

Pro-Israel supporters and others worried about campus safety have pointed to anti-Semitic incidents and allege that campuses are encouraging intimidation and hate speech.

"I've never felt more scared to be a Jew in America right now," said Skyler Sieradsky, a 21-year-old student of philosophy and political science at George Washington University.

"There are students and faculty standing by messages of hate, and standing by messages that call for violence."

Demonstrators, who include a number of Jewish students, have disavowed anti-Semitism and criticized officials equating it with opposition to Israel.

"People are here in support of Palestinian people from all different backgrounds... (compelled by) their general sense of justice," a 33-year-old graduate student at the University of Texas, Austin, who said he was Jewish and gave his name as Josh, told AFP.

US ally Israel launched its war in Gaza after the Hamas attack on October 7 that left around 1,170 people dead, according to an AFP tally of Israeli official figures.

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, authorities said, and the university cancelled events at the May 10 graduation ceremony.

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

At Emerson College in Boston, local media reported classes were cancelled Thursday after police clashed with protesters overnight, tearing down a pro-Palestinian encampment and arresting 108 people.

In Washington, students from Georgetown and George Washington University (GW) established a solidarity encampment on the GW campus Thursday.

Protests and encampments have also sprung up at New York University and Yale -- both of which also saw dozens of students arrested earlier this week -- Harvard, Brown University, MIT, the University of Michigan and elsewhere.

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

But the White House has also said the president supports freedom of expression at US universities.