ROCHESTER, Mich. (AP)  Classes at a suburban Detroit university were canceled indefinitely on Thursday after professors went on strike, upset over being asked to freeze their salaries a year after the university’s president received a $100,000 raise.

Oakland University, which has about 18,000 students, was to begin its fall semester on Thursday, but the teachers’ union authorized a strike the night before.

The union, which represents 450 faculty members at the public four-year institution, said it decided to strike after the university proposed a three-year wage freeze along with cuts in health insurance benefits.

“It was not something we wanted to do, because we are concerned about the welfare of our students,” said Sharon Mills-Wisneski, an assistant nursing professor, while standing on the picket line at the entrance to the campus here. “But it was something that needed to be done.”