At least fifteen anti-government protesters, including a nephew of Mir Hossein Mousavi, Iran’s opposition leader, were shot dead yesterday as the smouldering confrontation between the regime and the so-called Green Movement finally erupted.

Early reports put the number of dead at five, but as clashes continued late into the night, Iranian state television reported that the number of dead had risen to 15. The Ministry of Intelligence said more than 10 were members of “anti-revolutionary terrorist” groups.

Foreign journalists have been banned from Iran but Western newsrooms were inundated with mobile telephone footage of astonishing scenes: jubilant demonstrators attacking riot police and Basij militiamen, protesters gleefully setting light to a police station, Basiji building and motorbikes being captured from the security forces, detained protesters being freed from a police van while colleagues are carried away with blood pouring from gunshot wounds. Dozens were injured and more than 300 arrested.

Opposition websites said that demonstrators broke through cordons, blocked streets to thwart squads of baton-wielding motorbike police, hurled stones, stripped captured police officers of their uniforms and weapons, and burnt state-owned banks. Mobile telephone footage showed them holding aloft captured Basiji crash helmets as onlookers cheered. “People no longer fear,” one activist told The Times.