TEHRAN, Iran — Iranian security forces fired on stone-throwing protesters in the center of the capital Sunday in one of the bloodiest confrontations in months, opposition Web sites and witnesses said. At least five people were killed.
Some accounts of the violence in Tehran were vivid and detailed, but they could not be independently confirmed because of government restrictions on media coverage. Police, who denied using firearms, said dozens of officers were injured and more than 300 protesters were arrested.
The dead included a nephew of opposition leader Mir Hossein Mousavi, according to Mousavi's Web site, Kaleme.ir. The clashes were sure to deepen antagonism between the government and a reform movement that has shown resilience in the face of repeated crackdowns.
The street chaos coincided with commemorations of Shiite Islam's most important observance, Ashoura, fueling protesters' defiance with its message of sacrifice and dignity in the face of coercion.
Still, many demonstrators had not anticipated such harsh tactics by the authorities, despite police warnings of tougher action against any protests on the sacred day.
Amateur video footage purportedly from the center of Tehran showed an enraged crowd carrying away one casualty, chanting, "I'll kill, I'll kill the one who killed my brother." In several locations, demonstrators confronted security forces, hurling stones and setting their motorcycles, cars and vans ablaze, according to video footage and pro-reform Web sites.
Protesters tried to cut off roads with burning barricades.