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. "Death to the oppressor, whether it's the shah or the leader!" the students chanted, according to witnesses - making a comparison between Supreme Leader Ayatollah Ali Khamenei and the pro-U.S. shah, despised in Iran since his overthrow in 1979. The protests reflected how university students have revitalized the anti-government movement even as the mainstream opposition struggles to dent the power of President Mahmoud Ahmadinejad and Iran's clerical leadership.