A senior Iranian official says authorities detected sabotage at the country's heavy water reactor facility and neutralized it before any damage was done.
Semiofficial Fars news agency quoted Asghar Zarean, a senior official in charge of nuclear security at the Atomic Energy Organization of Iran, as saying Saturday that Iran's intelligence agencies were instrumental in uncovering the plot. He didn't provide further details.
Iran's Natanz uranium enrichment facility was the target of the so-called Stuxnet virus in 2010 that temporarily disrupted operation of centrifuges, a key component in nuclear fuel production.
Tehran says Stuxnet and other computer virus attacks are part of a concerted campaign by Israel, the US and their allies to undermine its nuclear program.