Iranian security forces opened fire on anti-government protesters in the capital, killing at least three people, opposition websites said.

The opposition supporters have gathered in an apparent attempt to revive anti-government demonstrations that followed presidential elections in June when the opposition claimed the polls had been rigged in favor of Iran's hardline leader Mahmoud Ahmadinejad.

The clashes on Sunday came as the country marks Ashura, a 10-day period of religious ceremonies which commemorate the death of Imam Hussein, a grandson of the Prophet Mohammed who was killed and beheaded in the Battle of Karbala in 680 AD by the armies of the Sunni caliph Yazid.

Al Jazeera reported on Sunday that the police had arrested a number of protesters.

"Hundreds of supporters of the Iranian opposition, mainly of reformist forces, have protested and chanted slogans supporting [Grand Ayatollah Hossein Ali] Montazeri and [opposition leader] Mir Hossein Moussavi," Al-Jazeera said.

"The police had earlier threatened to face any unlicensed gatherings, and this is what really happened on Saturday and Sunday," Al-Jazeera said.

TEHRAN, December 27 (RIA Novosti)