A new computer worm, Stuxnet, has infected staff computers at Iran's first nuclear power station.
The operating system at the Bushehr plant, which is to become operational, has not been harmed according to Bushehr project manager Mahmoud Jafari, reports the IRNA news agency.
The Stuxnet worm is capable of seizing control of industrial plants and has reached equipment linked to Iran's nuclear programme, which uses Siemens systems.
A team is now trying to remove the malicious software from several affected computers, according to Jafari.
Iran's ministry of industries head of the information technology council Mahmoud Liayi told IRNA that an electronic war has been launched against Iran.
To date, the worm has affected 30,000 computers in the country.