Opposition leader Mir Hossein Mousavi repeated his demand on Saturday that Iran's presidential vote must be annulled.
A letter addressed to the country's highest electoral authority was published on one of Mousavi's official Web sites Saturday night as eyewitnesses reported clashes between his supporters and security forces.
Mousavi renewed the demand in unprecedented defiance of Iran's supreme leader, who has effectively declared President Mahmoud Ahmadinejad the winner of the June 12 and ordered an end to protests by demonstrators who say Mousavi was the winner.
In the letter, Mousavi lists several allegations of voter fraud that calls proof the election should be held again. He didn't mention Khamenei by name or say whether he supported ongoing street protests.