The plot centred around Iran’s nuclear programme has arguably thickened with Tuesday’s accusation by Tehran that Israel was responsible for the attack in June on the centrifuge plant near Karaj.

The strike was intended to thwart talks in Vienna on reviving the tattered nuclear deal with world powers.

The treaty has virtually been reduced to irrelevance following Donald Trump’s withdrawal.

The orthodox establishment in Tehran has accused Israel of a sabotage attack that targeted a nuclear establishment near the Iranian capital. “The Zionist regime carried out this action to signal it can stop Iran and to say to world powers that there is no need to talk with Iran,” said the Iranian cabinet spokesman, Ali Rabiei.

“But whenever sabotage has happened, our strength has increased.”

However critical the charge relating to a potentially explosive issue, the reponse of Israel has thus far been muted though the conservative regime in Iran has been suitably prompt in internationalising the daring strike. Iran has offered few details on the attack which, it said, targeted a sprawling nuclear centre located in Karaj, a city about 40 km north-west of Tehran. On June 23, state TV said it was an attempted attack against a building belonging to Iran’s Atomic Energy Organization that left no casualties or damage.

Mr Rabiei said on Monday that the ceiling was damaged.

“Damage to equipment was not remarkable,” however.

His comments came several days after an Israeli report quoted experts to say the attack caused extensive damage, destroying or disabling all equipment in part of the site, which was allegedly used for producing centrifuges to enrich uranium.

The private Israeli intelligence group, The Intel Lab, said that the roof had largely been dismantled by Iran as part of rehabilitation activities following the attack. The dismantled roof allowed analysts to peek inside, where dark coloration indicated the presence of a large fire in the building, the smallest of three main structures at the site.

Iranian authorities did not specify which facility in Karaj had been targeted. There are two sites associated with Iran’s nuclear programme known to be in the area, including the Karaj Agricultural and Medical Research Center, founded in 1974. Authorities describe it as a facility that uses nuclear technology to improve the “quality of soil, water, agricultural and livestock production.” The area is located near various industrial sites, including pharmaceutical production facilities where Iran has manufactured its domestic coronavirus vaccine.