A spokesman for the University of Wisconsin-Milwaukee says at least 16 people have been detained by campus and city police following tuition protests that turned violent.

University spokesman Tom Luljak says about 125 to 150 students gathered at the student union Thursday about noon, then moved to an administrative building an hour later.

He says the protesters wanted to deliver petitions to the school chancellor. He says campus police allowed one person inside, and when she emerged she encouraged everyone to rush the building.

Luljak says when police turned them away, some protesters began throwing punches and tossing ice chunks.

A message left with representatives of the campus student government was not immediately returned.

CBS 58's Kelli Watson has more: