Police closed University Boulevard between Park and Euclid on Thursday night because of growing crowds celebrating the Wildcats' win over San Diego State in the NCAA Tournament.
Fans who were watching the game on televisions in packed bars began to empty into the streets about 10 p.m., creating crowds of hundreds, said Sgt. Pete Dugan, a Tucson Police Department spokesman.
Some fights were broken up and their participants dispersed, he said, but there have been no arrests.
Most of the people are celebrating and police are trying to keep them moving and not congregating, Dugan said.
Tucson police are directing traffic in the area and University of Arizona Police are assisting in controlling crowds.
There are no problems on campus or in UA residence halls, said UA Police Sgt. Filbert Barrera.
Stay with StarNet for updates.