Hundreds of pro-cleric militants and security forces clashed with Iranians throughout the capital for a fourth night, firing machine guns in the air and using tear gas and batons to put down any public opposition to the country’s hard-line regime.

Clashes erupted for a second straight night in Tehran, with anti-riot police and hard-line vigilantes beating up teenage demonstrators who had taken to the streets to denounce supreme leader Ayatollah Ali Khamenei.