Police fired tear gas today at Iranian protesters gathered in central Tehran, chanting slogans against President Mahmoud Ahmadinejad, witnesses said, as the nation marked Students Day on Monday.
The clashes came as a group of Iranian students issued a call for mass protests against Ahmadinejad to coincide with the annual event.
"Police fired tear gas at groups of protesters chanting slogans against President Mahmoud Ahmadinejad in Vali Asr intersection and Enghelab Street," a witness said, referring to prominent locations in central Tehran.
The protesters were chanting "Death to the Dictator" and "Do not be scared. We are all together," the witness said, adding that some protesters also beat up a policeman.
The incidents could not be independantly confirmed as foreign media have been banned from covering Monday's event.
Students of Tehran's prestigious Amir Kabir University had earlier urged protests against Ahmadinejad, in an online statement. "We are asking all people to come to universities so we can have one voice to protest at the coup d'etat," said the statement, issued by the group going under the name "Green university students of Iranian universities."
Green was the signature colour of main opposition leader Mir Hossein Mousavi's election campaign for the June 12 presidential poll. He lost to Ahmadinejad in what he claims was a "fraudulent" election staged to return the hardliner to power.