Police cleared a pro-Palestinian tent encampment at George Washington University in Washington DC on Wednesday and arrested demonstrators, hours after dozens marched to the home of the school’s president as city officials prepared to appear before Congress on the protest’s handling.

Washington DC Mayor Muriel Bowser and District of Columbia’s Metropolitan Police Department Chief Pamela Smith were called to testify on Wednesday afternoon at the Republican-led House Committee on Oversight and Accountability, but the hearing was cancelled after the arrests.

Tensions have ratcheted up in standoffs with protesters of the Israel-Hamas war on campuses across the United States, and increasingly in Europe.

Some colleges cracked down immediately. Others have tolerated the demonstrations. Some have begun to lose patience and call in police over concerns about disruptions to campus life and safety.

District of Columbia police said officers moved to disperse demonstrators because “there has been a gradual escalation in the volatility of the protest.” It said 33 arrests were made, including for assault on a police officer and unlawful entry. Some protesters were pepper sprayed as police blocked them from the camp.

George Washington University had warned of possible suspensions for continuing the camp on University Yard. Protesters carrying signs that read, “Free Palestine” and “Hands off Rafah,” also marched to school President Ellen Granberg’s home on Tuesday night.

“While the university is committed to protecting students’ rights to free expression, the encampment had evolved into an unlawful activity, with participants in direct violation of multiple university policies and city regulations,” a school statement said.

In France, police detained 86 people following an operation to remove students staging a pro-Palestinian occupation at the Sorbonne university in Paris, prosecutors said on Wednesday.

Those arrested in the police operation on Tuesday night were being held for a variety of public order offences, said the statement.

They include wilful damage, rebellion, violence against a person holding public authority, intrusion into an education establishment and holding a meeting designed to disrupt order. Some are also being held for participation in a group with a view to preparing violence or damage to property.

The day before police moved in, Prime Minister Gabriel Attal said there would never be a right to disrupt France's universities with such protests.

In the Netherlands, pro-Palestinian protesters built barricades at the University of Amsterdam, using desks and railings to block off the canalside entrance in the heart of the city as they vowed to stay put until the institution severs all ties with Israel.

Riot police used a bulldozer to knock down barricades at another University of Amsterdam site on Tuesday and detained 169 people, but said the university had not yet asked for similar intervention on Wednesday. (Agencies)