Riot police on Monday fired tear gas and shot paintballs at thousands of protesters who turned what they said was a Tehran rally in support of Arab uprisings into an anti-government demonstration. The clashes broke out at Tehran's prominent Azadi (Freedom) Square when crowds of opposition supporters began chanting "Death to Dictator!" -- a slogan used by protesters against President Mahmoud Ahmadinejad after the disputed 2009 presidential election.Witnesses said police fired tear gas and also shot paintballs at protesters who had gathered despite a ban by authorities.
Websites and witnesses said thousands of opposition supporters had taken to the streets of the capital in support of Arab revolts despite a heavy police deployment.
Iranian authorities had earlier surrounded the house of opposition leader Mir Hossein Mousavi to prevent him from attending the rally which regime-backers said was a ploy to stage anti-government protests similar to those which shook the foundations of the Islamic republic in 2009.
While Iran has backed the Arab uprisings in Tunisia and Egypt, the interior ministry in Tehran banned the Monday rally which Mr Mousavi and fellow opposition leader Mehdi Karroubi had sought to hold.