As hundreds of thousands of government supporters massed in Tehran toof the revolution that created the Islamic republic, gangs of hard-liners attacked senior opposition figures as they tried to attend the rallies - including the wife of the head of the reform movement.
Plainclothes Basiji militiamen beat 65-year-old Zahra Rahnavard with clubs on her head and back until her supporters formed a human ring around her and whisked her away, according to the Web site of her husband, Mir Hossein Mousavi.
The assault on Mousavi's wife took place in the square, and government supporters also blocked Mousavi himself from joining the protests, his Web site said.
The opposition claims that Ahmadinejad's victory in the June 12 election was fraudulent and that the true winner was pro-reform leader Mir Hossein Mousavi. Hundreds of thousands marched in the streets against the government in the weeks after the vote, prompting a massive wave of arrests.