Police in riot gear cleared a pro-Palestinian tent encampment at the University of Chicago on Tuesday after administrators who had initially adopted a permissive approach said the protest had crossed a line and caused growing concerns about safety.

University president Paul Alivisatos issued a message after officers blocked access to the school's Quad.

“The university remains a place where dissenting voices have many avenues to express themselves, but we cannot enable an environment where the expression of some dominates and disrupts the healthy functioning of the community for the rest,” he wrote.

Hundreds of protesters had gathered for at least eight days at the university until campus administrators warned them on Friday to leave the area or face removal.

On Tuesday, law enforcement dismantled the encampment. Officers later picked up a barricade erected to keep protesters out of the Quad and moved it toward the demonstrators, some of whom chanted, “Up, up with liberation. Down, down with occupation!”

Tensions have continued to ratchet up in standoffs with protesters on campuses across the US — and increasingly, in Europe — nearly three weeks into a movement launched by a protest at Columbia University.

Students have called for a ceasefire in Gaza and have demanded their schools divest from companies with ties to Israel.

Some colleges have cracked down immediately on protests against the Israel-Hamas war.

Since April 18, just over 2,600 people have been arrested on the campuses of 50 colleges and universities, according to figures based on reporting by the Associated Press and statements from universities and law enforcement agencies.

As pro-Palestinian protests continue to spread, the White House said President Joe Biden welcomes peaceful protests at college commencement ceremonies where he and other administration officials will speak.

White House spokesperson Karine Jean-Pierre said Biden welcomed peaceful protests on campuses and elsewhere, but would continue to condemn hate speech, antisemitism or violence.

"We have been very clear. We believe all Americans should have the right to peacefully protest," she added. "What we don't want to see is hate speech, violence."

Biden is due to give a commencement speech at Morehouse College in Atlanta on May 19.

He warned on Tuesday that the threat of antisemitism is growing in the United States, including on college campuses, joining a heated American debate about Jewish security, Zionism, free speech and support for Israel, in the country with the largest Jewish population after Israel.

Biden last week addressed the campus unrest, saying Americans have the right to protest "but not a right to cause chaos" through vandalism, breaking windows or shutting down campuses. (Agencies)