Iran ? Tens of thousands of students, many shouting “Death to the Dictator!” and burning pictures of Iran’s supreme leader, took to the streets on more than a dozen campuses Monday in the biggest anti-government protests in months.

Riot police and pro-government Basij militiamen on fleets of motorcycles flooded Tehran’s main thoroughfares, beating men and women with clubs as crowds of demonstrators hurled bricks and stones. Some protesters set tires and garbage cans ablaze.

“Death to the oppressor, whether it’s the shah or the leader!” the students chanted, according to witnesses — making a daring comparison between Supreme Leader Ayatollah Ali Khamenei and the pro-U.S. shah, despised in Iran since his overthrow in the 1979 Islamic Revolution.

The protests reflected how university students — the driving force of the 1979 Islamic Revolution — have revitalized the anti-government movement even as mainstream opposition politicians struggle to dent the power of President Mahmoud Ahmadinejad and Iran’s clerical leadership.