Up to 40 Iranian police officers have been injured in clashes with demonstrating students in Tehran.
Senior staff have been replaced at Tehran University
Students were demonstrating about the appointment of a new college head at Tehran University and the forced retirement of some professors.
There were also protests at Tehran's Amirkabir University about activities of the hardline Basij militia.
The militia had "interfered in elections" for the Islamic Students Association, a pro-reform group.
Iran's student news agency ISNA said protestors shouted "Death to reactionaries and dictatorship!" and "We don't want the Islam of the Taleban".
Amirkabir University is one of Iran's most prestigious technical colleges and research centres.