Shortly after the Wildcats’ overtime loss to Wisconsin Saturday night, it seemed all might remain calm.

But in less than half an hour, some in the initially peaceful crowds leaving university-area bars and restaurants after the NCAA tourney game began pelting Tucson police officers with cans, bottles and fireworks.

Officers in riot gear responded by launching pepper balls and pepper spray in their attempts to break up the crowds.

There were no reports of injuries to fans or officers, but 15 people were arrested for offenses such as resisting arrest, disorderly conduct and unlawful assembly, Tucson police Sgt. Pete Dugan said. Of those arrested, 14 were released, and one was sent to Pima County jail. He said those advancing on officers were arrested. The street was clear and the crowd was gone by late Saturday.

At one point, the rowdy crowd surrounded officers in cruisers and on motorcycles.

About 45 minutes into the fracas, Tucson police called in additional officers to help quell the crowds.

A Tucson police official couldn’t say exactly how many officers were on scene or patrolling by air, but a reporter in Main Gate Square estimated 50 to 75 officers were trying to break up the crowd.

Just after the game ended, there was a heavy police presence on North Fourth Avenue, and the avenue was shut down between Eighth and Ninth streets. But the crowd was quiet and eventually the officers moved off to provide support closer to the university.

The crowds near the university were largely dispersed by 10 p.m.

Includes information from the Associated Press