A video has emerged which shows crowds rioting against the Iranian regime.

The riot broke out in Tehran on the weekend when the Iranian Chastity Police attempted to arrest a young woman they said was inappropriately dressed.

Witnesses say the young woman resisted arrest, which caused the police to push and beat her.

The sight of the woman being beaten prompted a bystander to come to her aid, but he was also roughed-up by the security forces.

Dozens of Iranians who were present at the scene began rioting and setting rubbish on fire.

The riot was captured on numerous cell-phone cameras and shows people shouting slogans against the police and government.

The crowed reportedly called out against Iranian President Mahmoud Ahmadinejad.

Efforts by the Iranian Revolutionary Guard and Chastity Police to enforce the Islamic dress code on Iranian women has caused thousands of women to be detained for failing to uphold the dress code.