Tehran and other cities have seen the largest street protests and rioting since the 1979 Iranian Revolution. Supporters of reform candidate Mir Hossein Mousavi, upset at their announced loss and suspicions of voter fraud, took to the streets both peacefully and, in some cases, violently to vent their frustrations. Iranian security forces and hardline volunteer militia members responded with force and arrests, attempting to stamp out the protests – meanwhile, thousands of Iranians who were happy with the election outcome staged their own victory demonstrations. Mousavi himself has been encouraging peaceful demonstrations, and called for calm at a large demonstration today (held in defiance of an official ban), as Iran’s supreme leader Ayatollah Ali Khamenei has just called for an official inquiry into accusations of election irregularities.