At least 457 people were arrested during rioting in Iran''s capital on Saturday as protests continued against the country''s disputed presidential election, Mehr news agency reported on Monday.

Tehran has been swept by mass demonstrations over alleged ballot fraud in the landslide reelection of hardline President Mahmoud Ahmadinejad on June 12. Official results gave the incumbent 63% of the vote, with reformist challenger Mir Hossein Mousavi getting 34%.

Iran''s supreme leader, Ayatollah Ali Khamenei, said during Friday prayers that the margin of victory was too great for the election to have been stolen, and declared his support for Ahmadinejad.

On Saturday opposition protests turned into street fights as Mousavi called on his supporters in a web message: "People won''t respect those who take power through fraud."

Iranian officials said the daughter and four other relatives of former President Hashemi Rafsanjani were among those arrested. Press TV later said the four relatives had been released while Faezeh, a 46-year-old reformist politician who has openly backed Mousavi, remained in custody.

Mousavi called on his supporters to continue "showing restraint," saying in a statement on his website on Sunday that the mass arrests "will create a rift between society and the country''s armed forces."

At least 13 protesters were killed and 20 wounded on Saturday, Press TV said, citing local officials. Meanwhile, some hospital sources said 19 people had died as a result of clashes with police.

The FARS news agency reported that police said some 40 officers were wounded during the riots and more than 30 government buildings were damaged.