AUSTIN, April 25 — Increasingly confrontational pro-Palestinian rallies by students protesting the death toll from the Israel-Hamas conflict erupted across US college campuses yesterday, triggering tense faceoffs with police in Texas and California.

At New York’s Columbia University — the epicentre of the expanding protests — Republican House of Representatives Speaker Mike Johnson said that if the demonstrations were not contained quickly it would be "an appropriate time for the National Guard”.

It was a provocative threat to make on a US campus. Students at Columbia have already evoked the spectre of 1970 demonstrations at Kent State University in Ohio that saw the National Guard fire into a crowd protesting the Vietnam war, killing four unarmed students and wounding nine.

And police have already faced off against students since the protests began at Columbia last week, with hundreds arrested in recent days.

Johnson spoke to media across from the lawn where Columbia students first set up their protest encampment last week.

He said he intended to demand US President Joe Biden "take action,” and warned that the demonstrations "place a target on the backs of Jewish students in the United States.”

"Enjoy your free speech,” he told booing students.

Earlier, Biden’s spokeswoman Karine Jean-Pierre said he backed free speech on US campuses.

"The president believes that free speech, debate and non-discrimination on college campuses are important,” she told reporters.

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

The student protesters say they are expressing solidarity with Palestinians in Gaza, where the death toll has topped 34,200 so far, according to the Hamas-run health ministry, and calling on Columbia and other universities to divest from companies with ties to Israel.

The demonstrators — including a number of Jewish students — say they’ve disavowed instances of anti-Semitism.

But pro-Israel supporters, and others worried about campus safety, have pointed to anti-Semitic incidents and argued that campuses are encouraging intimidation and hate speech.

Israeli defence minister Yoav Gallant also weighed in on social media, saying the protests are "not only anti-Semitic, but also inciting terrorism”.

‘Down with occupation’

Johnson’s visit to Columbia came as Texas deployed police in riot gear and mounted state troopers at the University of Texas campus in Austin after hundreds of protesters there staged a boisterous walkout, chanting "down with occupation”.

The Texas Tribune said at least 17 people were detained.

Police were also called after at least 100 students began what they called an occupation on the campus of the University of Southern California, in Los Angeles, with media reporting that the demonstration was mostly peaceful.

Students have also launched protests at several other schools, including Yale, MIT, UC Berkeley, the University of Michigan and Brown.

Social media images showed an encampment taking shape at Harvard University near Boston.

Classes were moved online and other on-campus activities cancelled at California State Polytechnic University, Humboldt, after protesters barricaded themselves in a campus building.

More than 130 people were arrested at a pro-Palestinian protest at New York University Monday night.

And police at the University of Minnesota reportedly arrested nine people at a pro-Palestinian encampment.

NBC reported that the FBI is coordinating with universities over anti-Semitic threats and possible violence in connection with the ongoing wave of protests.

Columbia deadline extended

Before Johnson’s visit to Columbia an uneasy truce was in place between students and officials, after a deadline to forcibly disperse their protest encampment expired.

Tensions at the school had reached their peak last week, when more than 100 people were arrested after the university president Minouche Shafik called in the police.

University officials had set a deadline of midnight Tuesday to resolve the unrest, but as more people joined the protest overnight the school extended the deadline by 48 hours early Wednesday, students said on social media.

They agreed to the ongoing talks after the school promised not to call the police or National Guard, organisers with Columbia University Apartheid Divest said, calling the concession an "important victory.”

"We fear that Columbia is risking a second Jackson State or Kent State massacre,” the group said in the social media post.

Eleven days after the Kent State shootings, Jackson State in Mississippi also saw police confront student protesters in 1970 and open fire, killing two and injuring 12. — AFP