Police break up pro-Palestinian demos in Amsterdam, Berlin
At the University of Amsterdam, images on public broadcaster NOS showed police baton-charging protesters and smashing up tents at around 4:00 am (0200 GMT), after they refused to leave the campus.
"The demonstration took on a violent nature because later in the evening massive stones were removed from the ground," police said in a statement.
Violence briefly erupted on Monday evening when a small group of counter-protesters wielding flares stormed the main protest.
Demonstrators blocked off some roads to the university, after which police broke up the protest to enable access by emergency services.
Some students hurled stones and fireworks at the officers when they broke up the demo, said police, and more than 120 were arrested.
On Tuesday morning, police began releasing some of those arrested but dozens were still in custody.
The protesters have urged the university to break ties with Israel because of its military offensive in Gaza.
The war in the Gaza Strip was sparked by an unprecedented October 7 attack on Israel by the Palestinian group Hamas, which resulted in the deaths of more than 1,170 people, mostly civilians, according to an AFP tally of Israeli official figures.
Militants also seized around 250 hostages, with an estimated 128 remaining in Gaza, including 35 the Israeli military says are dead.
Vowing to destroy Hamas, Israel launched a retaliatory offensive that has killed at least 34,789 people in Gaza, mostly women and children, according to the Hamas-run territory's health ministry.
"We are not just here to camp for two days. We are here to demand that this university puts an end to its complicity in the genocide," one of the demonstration's organisers told Dutch news agency ANP on Monday.
The university has published a list of its collaborations with Israel, mainly student exchanges with universities and research projects that involve Israeli academics.
The university "will under no circumstances contribute to warfare in any way, and we also do not intend to participate in exchanges in the field of military-related education", it said on its website.
Police also cleared a pro-Palestinian demonstration at Berlin's Freie Universitaet, after up to 80 people set up a protest camp in a courtyard of the campus early Tuesday.
The protesters, some of whom wore the keffiyeh scarf that has long been a symbol of the Palestinian cause, sat in front of tents and waved banners.
They later tried to enter rooms and lecture halls and occupy them, according to the university, which said it then called in the police to clear the protest.
Videos on social media showed some protesters being carried away by officers.
Property was damaged and charges have been filed while teaching in some buildings was suspended for the day, the university said.
Berlin police said some arrests were made for incitement to hatred and trespassing.
Pro-Palestinian student demonstrations have generally been more muted in Germany, which is a staunch backer of Israel, than elsewhere.
The protests in Amsterdam and Berlin followed similar actions at universities around the world, notably in the United States, where some schools have cancelled graduation ceremonies.