In the latest warning to the opposition, Iran's supreme leader on Wednesday called questioning the results of the June presidential election "a crime."
Ayatollah Ali Khamenei, who has the final say on all state matters in Iran, did not go so far as to order the arrest of top opposition leaders, as called for by hardliners.
Opposition figures Mir Hossein Mousavi, Mahdi Karroubi and former President Mohammad Khatami remain defiant, saying the elections were marred by massive vote fraud and refuse to recognize the government as legitimate.
Protests after the elections were crushed in a heavy crackdown that resulted in hundreds of arrests in the worst unrest since the Islamic Revolution. The opposition says at least 72 protesters were killed, while the government has confirmed 30.