Thousands of students have taken to the streets of Tehran to vent their opposition to Iranian President Mahmoud Ahmadinejad and his disputed June re-election.
Some reports say security forces fired live ammunition near demonstrators and beat them with batons. Foreign journalists are banned from reporting on the rallies, so there is no independent confirmation of the reports.
The demonstrations were staged on Iran's Students Day, when rallies are traditionally held to commemorate the killing of three students in 1953 under the former Shah of Iran.
Opposition students protesting inside Tehran University held signs and chanted "Death to the dictator".
Meanwhile, about 2,000 pro-government students staged a counter-protest on the campus, waving pictures of Supreme Leader Ayatollah Ali Khamenei and chanting "Death to the hypocrites".
At times, the two side came to blows, but there are currently no reports as to whether anyone was seriously injured.
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