Police forcibly dismantled a pro-Palestinian encampment at the Art Institute of Chicago on Saturday and arrested dozens of protesters, hours after demonstrators had gathered in a garden at the institute and set up tents.

Some of the demonstrators were students at the School of the Art Institute of Chicago, which is affiliated with the institute, the school said in a statement.

Chicago police said on social media that officers had removed the protesters at the school’s request. A Chicago Police spokesperson said Sunday that 68 people had been arrested and charged with trespassing.

The protesters set up the encampment in the North Garden, which is part of the Art Institute of Chicago museum, at about 11 a.m. Saturday, police said. While encampments at some other U.S. schools during the recent wave of pro-Palestinian protests have stood for days or even weeks before police action, in this case police said that officers “immediately responded” to maintain the safety of the protesters and the public.

The People’s Art Institute, the organizers of the protest, said on social media that the demonstrators’ demands included that the institute formally condemn Israel’s treatment of the Palestinians, remove any programs that legitimize the “occupation of Palestine” and divest from any individuals or entities that support Israeli occupation of Palestinian territory. Photos that the group uploaded to social media showed a sign in the encampment that read “Hind’s Garden,” a reference to Hind Rajab, a 6-year-old Palestinian girl who was killed this year in Israel’s war against Hamas in the Gaza Strip.

The school said that it had offered protesters an alternate venue and promised students that they would not face academic sanctions or charges if they relocated there.

The statement added that some protesters “surrounded and shoved a security officer and stole their keys to the museum, blocked emergency exits and barricaded gates.”

After about two hours of negotiations, the school asked officers to remove the protesters, police said. Officers issued warnings and eventually removed and arrested protesters, police said.

Videos posted by the organizers showed police forcibly pulling demonstrators out of the human chain they had formed outside the garden while some of the protesters chanted, “Who do you protect? Who do you serve?”

This article originally appeared in The New York Times.