The toll was the result of clashes that broke out between demonstrators and security forces as large crowds gathered for Ashura, a major religious observance.

Four people were reported killed in the fighting, according to Iranian state-run Press TV. Without giving an exact number of casualties, Radan said those killed included one person who fell off a bridge and two others who were killed in a car accident during the protests.

Tehran Police Chief Azizollah Rajabzadeh denied any protesters were killed by security forces.

Since the disputed presidential elections in June, protesters have turned public gatherings into rallies against President Mahmoud Ahmadinejad, who was declared the overwhelming winner of the race.