TEHRAN, Feb. 2 (UPI) -- Iranian intelligence officials said they arrested an unnamed aide to opposition leader Mir Hossein Mousavi on charges he was in contact with Western officials.
Intelligence officials said a Mousavi adviser confessed to the "crime of espionage" in relation to his contact with Western intelligence agencies, reports Radio Zamaneh, an Amsterdam-based Persian news agency.
The so-called Iranian Cyber Army hacked Radio Zamaneh's Web site during the weekend, issuing a warning that "all treasonous mercenaries" could be harassed.
Tehran rounded up scores of dissidents it blames for plotting against the government, including two German diplomats.
Demonstrations on the Shiite holy day of Ashura in December turned violent, leaving several protesters dead and government buildings in flames.
Opposition to the contested presidential election that brought a second term to Iranian President Mahmoud Ahmadinejad evolved into a challenge to the clerical regime in Tehran. Mousavi was the leading challenger to Ahmadinejad in the June contest.
Supporters of the so-called opposition Green Movement are said to be planning major demonstrations to mark the anniversary of the Islamic Revolution on Feb. 11.
Tehran said it would allow more than 100 foreign journalists to cover the Feb. 11 events.