The University of Southern California (USC) in Los Angeles has cancelled its main graduation ceremony on 10 May, citing safety measures.

The move comes as protests have erupted on dozens of campuses across the US over the Israel-Gaza war.

At Atlanta's Emory University, 28 demonstrators were arrested on Thursday after refusing to leave.

In New York City, Columbia University dropped a Thursday night deadline for an end the encampment on its campus.

In a statement, USC said it would "not be able to host the main stage ceremony that traditionally brings 65,000 students, families and friends" to its campus.

On Wednesday, police arrested at least 93 people at the campus for trespassing, and ordered the dismantling of an encampment.

USC announced earlier this month that Muslim student Asna Tabassum would no longer be permitted to deliver a speech as valedictorian due to unspecified security threats.

Demonstrators at Emory said they were supporting Palestinians but also voicing their objection to a police training centre in Atlanta.

Plans for the centre have been controversial locally and the project has been dubbed "Cop City" by opponents.

Emory's police force said protesters had "pushed past" officers protecting the area set up for commencement on Thursday morning.

The force acknowledged that chemical irritants had been released as part of crowd control measures, though they said the step had been taken after some members of the crowd threw "objects" at officers.Atlanta Police also confirmed using chemical irritants but denied reports they had fired rubber bullets at protesters.

Atlanta police used chemicals to disperse the protesters but deny reports that they fired rubber bullets

One protester shown on video being detained by police identified herself as Noelle McAfee, chair of Emory's philosophy department.

Ms McAfee said she was observing what she described as a peaceful protest when police began to move in and the protesters started to march.

"It went from a peaceful protest to mayhem in the matter of a minute," she said. She said she had frozen and been quickly detained.

The latest wave of campus protests began after officials at Columbia University called in police to clear a new protest encampment and more than 100 people were arrested.

Activists have been calling for universities to "divest from genocide" and to stop investing large school endowments in companies involved in weapons manufacturing and other industries supporting Israel's war in Gaza.

Police try to handle protesters on the campus of City College of New York

Israel is currently facing a case brought by South Africa at the International Court of Justice alleging that it is committing genocide against the Palestinians, an accusation Israel has rejected as "baseless".

Chisato Mimura, a law student and protest leader at Yale University in Connecticut, told the BBC that activists were upset at President Joe Biden as well as their school officials for "quite literally funding and equipping the weapons used in genocide".

"What they're doing is completely putting their full weight behind it," she said. "We are well aware of the prominent role they are playing."

Some of the protests on US campuses have been accused of antisemitism. A number of Jewish students have said they have felt unsafe at Columbia and at other universities, although other Jewish students have joined the demonstrations.

The protests have spread across the country – this encampment was set up at the University of Michigan

At Columbia, where the wave of campus protests began last week, the university administration had given protesters a Thursday night deadline to agree a deal to end the disruption.

Spokesperson Ben Chang said that, if no agreement was reached, "we will have to consider options for restoring calm to campus".

However, in a statement late on Thursday, the university announced it had dropped the deadline, saying that "talks have shown progress" and would continue.

Palestinian flags around a statue of George Washington at the university of the same name in the US capital on Thursday

Earlier on Thursday, Minnesota Democratic congresswoman Ilhan Omar visited the campus. Her daughter, Isra Hirsi, was one of the protesters cleared from the university by police last week.

"This is a movement that started with only 70 students," Ms Omar told the BBC. "And because Columbia University decided to crack down on them and violate their First Amendment [rights], this has now spread nationally and internationally."

In other recent developments:

In Syracuse, New York, President Biden was greeted by around 100 protesters with signs reading "Genocide Joe" and other slogans as he attended an official event

A camp was set up at Northwestern University near Chicago, where school officials moved to limit the use of tents. Police were on campus and ordered protesters to leave, but no arrests were reported

Organisers of the Uncommitted movement, which has encouraged Democratic primary voters to reject President Biden, said that they would join the student activists camping at the University of Michigan

Students at Georgetown University, George Washington University and American University protested in Washington DC

Brandeis University in Boston, where one-third of the student body is Jewish, said it would extend its transfer deadline to accommodate students who felt targeted and attacked at other schools

California State Polytechnic University, Humboldt said its campus could remain closed until next week because of protesters occupying buildings

Other campuses to see protests and encampments include Harvard, Brown, MIT and Indiana University

The war began when Hamas-led gunmen carried out an unprecedented attack on southern Israel on 7 October, killing about 1,200 people - mostly civilians – and taking 253 others back to Gaza as hostages.

More than 34,180 people – most of them children and women – have been killed in Gaza since then, the territory's Hamas-run health ministry says. (BBC)

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