Police detained nearly 200 people at three US universities on Saturday as they cleared pro-Palestinian encampments, in the latest campus clashes triggered by protests over Israel's war against Hamas.

On the East Coast, police in Boston detained about 100 people while clearing a protest camp at Northeastern University, with social media posts showing security forces in riot gear and officers loading tents onto the back of a truck.

The action was taken after some protesters resorted to "virulent anti-Semitic slurs, including 'Kill the Jews,'" Northeastern University said in a statement on social media platform X.

On the opposite side of the country, Arizona State University police arrested 69 people for trespassing after the group set up an "unauthorized encampment" on campus.

Arizona State officials said a protest group -- "most of whom were not ASU students, faculty or staff" -- had set up a camp Friday and then ignored repeated orders to disperse. 

And in the US heartland, police at Indiana University arrested 23 people as they cleared a campus protest camp, the Indiana Daily Student newspaper reported. 

Police with shields, batons and other riot gear broke through a line of protesters who had linked arms, tackling those who did not move, the paper said.

Balancing act

The campus activists are calling for a ceasefire in Israel's war with Hamas, as well as for colleges to sever ties with the country and with companies they say profit from the conflict.

The protests have posed a major challenge to university administrators who are trying to balance commitments to free expression with complaints that the rallies have veered into anti-Semitism and hate speech.

Police have carried out large-scale arrests at universities in recent days, at times using chemical irritants and tasers to disperse demonstrators.

In a statement on X, Northeastern said the area on campus where the protests were held was now "fully secured" and "all campus operations have returned to normal."

The school said it made the move after "what began as a student demonstration two days ago was infiltrated by professional organizers with no affiliation to Northeastern."

It added that detained individuals who produced a valid school ID have been released and will face disciplinary proceedings, not legal action.

"Those who refused to disclose their affiliation were arrested," the school said.

'Zionists don't deserve to live'

Dozens of students remained encamped Saturday at the University of Pennsylvania, despite the college president ordering disbandment after what he said were "credible reports of harassing and intimidating conduct."

Meanwhile, Columbia University in New York, where the protests originated, was relatively calm. Officials there announced Friday that they would not be calling police back to campus after more than 100 people were arrested last week.

"To bring back the NYPD at this time would be counterproductive, further inflaming what is happening on campus, and drawing thousands to our doorstep who would threaten our community," school leaders said in a statement, referring to the New York Police Department.

The decision was made even as Columbia signalled it had barred from campus Khymani James, a leader of the campus protests who had said in a video in January that "Zionists don't deserve to live," and "Be grateful that I'm not just going out and murdering Zionists."

"Chants, signs, taunts and social media posts from our own students that mock and threaten to 'kill' Jewish people are totally unacceptable, and Columbia students who are involved in such incidents will be held accountable," the school said.

California State Polytechnic University, Humboldt announced it was closing campus until the end of the semester, with instruction and work continuing remotely after protesters repeatedly attempted to "break into multiple locked buildings with the intention of either locking themselves in, vandalizing or stealing equipment."

Canada saw its first campus protest camp spring up Saturday at McGill University. The school in Montreal said such encampments, which are not permitted, increase "the potential for escalation and confrontation, as we have seen at some colleges throughout the US." 

Hamas militants staged an unprecedented attack on Israel on October 7 that left around 1,170 people dead, according to an AFP tally of Israeli official figures. 

Palestinian militants also took roughly 250 people hostage. Israel estimates 129 remain in Gaza, including 34 the military says are dead.

Israel's retaliatory offensive has killed at least 34,388 people in Gaza, mostly women and children, according to the Hamas-run territory's health ministry.