CHICAGO — Raucous cheers broke out among a large portion of the crowd that had gathered for a rally by Republican presidential candidate Donald Trump. The spark was Trump’s decision to cancel the event after protesters packed the arena and organizers feared there would be violence.

Some isolated confrontations took place after the cancellation and police reported arresting five people. Many anti-Trump attendees had rushed onto the floor of the University of Illinois at Chicago Pavilion, jumping up and down with their arms up in the air.

“Trump represents everything America is not and everything Chicago is not,” said Kamran Siddiqui, 20, a student at the school who was among those celebrating. “We came in here and we wanted to shut this down. Because this is a great city and we don’t want to let that person in here.”

Some supporters of the Republican front-runner started chanting “We want Trump! We want Trump!” in response to the celebrations.