After a top Iranian cleric and official has criticized the authorities for their handling of the country's disputed presidential election, defiant opposition supporters take to streets of Tehran.

Clashes erupted outside the Tehran University campus on Friday after Ayatollah Akbar Hashemi-Rafsanjani led the weekly prayers there.

Ayatollah Rafsanjani is a former president and one of the most influential cleric who heads two powerful state institutions, the Expediency Council and the Assembly of Experts.

Rafsanjani criticized the Guardian Council, the electoral watchdog, for failing to allay doubts about the outcome of the presidential election, which according to him, did not benefit anyone in Iran.

He also called for the release of those detained in the course of post-election events.

Following the prayers, thousands of supporters of opposition leader Mir-Hossein Mousavi, who was defeated by the incumbent President Mahmoud Ahmadinejad, demonstrated at various locations around the Tehran University campus.

Riot police used tear gas to disperse the crowd, who spontaneously staged the demonstration in defiance of a ban on such gatherings.

Mousavi has claimed that the June 12 vote was rigged, questioning the legitimacy of the incoming administration.

President Ahmadinejad, however, has asked the opposition to abandon its pre-election mentality and look forward to the future of the country.

During the Friday prayers, Ayatollah Rafsanjani said he hoped his remarks -- in which he offered suggestions for the authorities to end the post-election "crisis" -- would mark a new period for the Iranian nation to work toward "unity."

MD/MMN