Security forces have raided the office of Iran's top opposition leader and seized computers after days of intimidating visitors with a heavy force presence around the building.
The raid on Mir Hossein Mousavi's office on Wednesday night points to a stepped-up campaign to harass the leaders of the country's besieged and dispirited pro-reform movement. Relentless crackdowns over the past year have driven opposition activists from the streets after an initial outpouring to protest the June 2009 presidential election, which they say was fraudulent.
Earlier in September, pro-government mobs attacked the home of another opposition leader, Mahdi Karroubi, with homemade bombs and beat one of his bodyguards unconscious.
Security forces have been deployed around Mousavi's office for several weeks, briefly detaining and questioning visitors on their way out of the building, said Thursday's report on the Kaleme website.
The head of Mousavi's office, Hamid Mohseni, was arrested on Monday, it said.
Mousavi was not in his office when the raid took place.
Mousavi and Karroubi are the two pro-reform candidates who ran against Ahmadinejad in the 2009 election. Mousavi said he was the rightful winner of the vote, and tens of thousands of Iranians poured into the streets to challenge Ahmadinejad's re-election and ultimately the ruling system itself.
Over the months that followed, a heavy crackdown swept protesters from the streets.
Adding to the pressure on the opposition, Tehran chief prosecutor Abbas Jafari Dowlatabadi issued a new warning that the movement's leaders could be brought to trial, Iranian newspapers reported Thursday.
The courts have tried more than 100 opposition members and political activists throughout the postelection unrest, accusing them of seeking to topple the ruling system. More than 80 of them have been sentenced to prison terms ranging from six months to 15 years. Ten defendants sentenced to death have appealed their rulings.
In August, the manager of Mousavi's presidential campaign, Qorban Behzadiannejad, was sentenced to five years in prison on charges related to the postelection unrest.