The protests were the largest in months, as university students -- a bedrock of support for the pro-reform movement -- sought to energize the opposition with rallies at campuses across the country. The opposition has been reeling under a fierce crackdown since turmoil erupted over the disputed presidential election in June.
Thousands of riot police, Revolutionary Guard forces and pro-government Basij militiamen flooded the area around Tehran University since the morning, vowing to prevent any unrest from spilling out into the streets.
Banners and signs bearing slogans from Supreme Leader Ayatollah Ali Khamenei blanketed the tall campus fence, hiding whatever took place inside. Cell phone networks around the universities were shut down, and police and members of the elite Revolutionary Guard surrounded all the university entrances and were checking IDs of anyone entering to prevent opposition activists from joining the students, witnesses said.
The heavy clampdown raised fears of an escalation of violence during Monday's clashes.
