FILE PHOTO: A view of the Natanz uranium enrichment facility 250 km (155 miles) south of the Iranian capital Tehran, March 30, 2005. REUTERS
Iran on Monday accused arch-foe Israel of sabotaging its key Natanz nuclear site and vowed revenge for an attack that appeared to be latest episode in a long-running covert war.
Iran's semi-official Nournews website said the person who caused an electricity outage in one of the production halls at the underground uranium enrichment plant had been identified. "Necessary measures are being taken to arrest this person," the website reported, without giving details about the person.
The incident occurred amid diplomatic efforts by Iran and the United States to revive Tehran's 2015 nuclear deal with major powers, an accord Israel fiercely opposed, after former U.S. President Donald Trump abandoned it three years ago.
Last week, Iran and the global powers held what they described as "constructive" talks to salvage the deal, which has unravelled as Iran has breached its limits on sensitive uranium enrichment since Trump reimposed harsh sanctions on Tehran.
Iranian authorities described the incident a day earlier as an act of "nuclear terrorism" and said Tehran reserved the right to take action against the perpetrators.
On Monday, Foreign Minister Mohammad Javad Zarif explicitly blamed Israel. "The Zionists want to take revenge because of our progress in the way to lift sanctions...They have publicly said that they will not allow this. But we will take our revenge against the Zionists," Zarif was quoted by state TV as saying.
Multiple Israeli media outlets have quoted unnamed intelligence sources as saying the country's Mossad spy service carried out a successful sabotage operation at the underground Natanz complex, potentially setting back enrichment work there by months. Israel has not formally commented on the incident.
The incident took place a day after Tehran, which has insisted it wants only peaceful nuclear energy not nuclear bombs from the enrichment process, launched new advanced centrifuge machines at Natanz.
"All of the centrifuges that went out of circuit at Natanz site were of the IR-1 type," Foreign Ministry spokesman Saeed Khatibzadeh told a news conference, referring to Iran's first generation of enrichment machines more vulnerable to outages.
"Our nuclear experts are assessing the damage but I can assure you that Iran will replace damaged uranium enrichment centrifuges in Natanz with advanced ones."
Modernised centrifuges can refine uranium to higher fissile purity at a much faster rate, helping accumulate a stockpile that could shorten Iran's route to a nuclear weapon, if it chose to develop them, than the IR-1 that still predominates in Natanz's production halls.
The 2015 deal only allows Iran to enrich with up to 5,060 IR-1 machines, in a plant designed to house around 50,000, but it has begun enriching at Natanz with hundreds of advanced centrifuges including the IR-2m.
Despite strong Israeli opposition, U.S. President Joe Biden's administration is committed to rejoining the deal if the Islamic Republic returns to full compliance with restrictions on nuclear fuel production.
Khatibzadeh said nuclear talks would resume on Wednesday in Vienna. Diplomatic headway has been made, delegates said on Friday. Iran insists all U.S. sanctions crippling its oil-based economy must be lifted first before it stops accelerating enrichment and restores caps on the process.
At a ceremony on Sunday, Israeli Prime Minister Benjamin Netanyahu made no direct reference to Natanz, though said: "The fight against Iran's nuclearisation...is a massive task."
There have been sporadic episodes of sabotage and outages at Iranian nuclear installations for over a decade, for which Tehran has blamed Israel, which regards the Iranian uranium enrichment drive as a menace to its existence.
In 2010, the Stuxnet computer virus, widely believed to have been developed by the United States and Israel, was discovered after it was used to attack Natanz, causing damaging breakdowns of centrifuge cascades that refine uranium.
In July last year, a fire broke out at Natanz that Iran said was an attempt by Israel to sabotage its enrichment activity.
Iran also accused Israel of responsibility for last November's ambush killing outside Tehran of Mohsen Fakhrizadeh, who was regarded by Western intelligence services as the mastermind of a covert Iranian nuclear weapons programme. Israel has neither confirmed nor denied involvement.
In addition, since Biden took office in January pledging to reverse Trump's efforts to wreck the nuclear deal, there have been a series of attacks on Iranian- and Israeli-owned shipping for which the two sides have traded blame.