Police in Paris entered France's prestigious Sciences Po university on Friday and removed student activists who had occupied its buildings in protest against Israel's conduct in its war against Hamas in Gaza.

A Reuters witness saw police go into the buildings and take out many of the 70-odd protesters inside. Unlike in some college campuses across the United States, the French protests have been peaceful and there were no signs of violence as the students were brought out of the buildings.

Sciences Po has become the epicentre of French student protests over the war and academic ties with Israel, which have spread across France but have remained much smaller in scale than those seen in the United States.

The university was closed for the day on Friday, with a heavy police presence around its main building.

Jack, a Sciences Po student who declined to give his surname, said he was one of around 70 students who spent Thursday night occupying one of the university's main buildings in central Paris.

He told Reuters on Friday morning that protesters had declined an ultimatum by university officials to clear large parts of the building and restrict their movement to a determined smaller area.

A Sciences Po spokesperson, speaking before the police intervention, said the university was seeking a "negotiated solution to end the standoff" with its students, and that some of the its satellite campuses in Reims, Le Havre and Poitiers were also affected by protests.

Sciences Po Lyon, an unaffiliated university in France's third largest city, was also blocked by protesting students on Friday, as well as the Lille school of journalism, images broadcast by French news channels showed.

Sciences Po's director Jean Basseres on Thursday rejected demands by protesters to review its relations with Israeli universities, prompting protesters to continue their movement with at least one person entering a hunger strike, according to a student speaking on behalf of the protesters.

Samuel Lejoyeux, who heads the Union of Jewish Students of France, said French student protests had remained more peaceful than those in the United States as there was a greater desire for dialogue in France.

"With the overwhelming majority of students at French universities, including Sciences Po, it is still possible to have a debate. I even think there is an increased hunger for debate," he told broadcaster BFM TV.