In a statement on Friday the International Atomic Energy Agency, IAEA, said that although its inspectors were not present at the time of a fire/explosion at Iranian nuclear facility in Natanz, the Islamic Republic authorities had informed the U.N. nuclear watchdog of the incident.
"Iran also informed the IAEA late on Thursday that the fire was quickly extinguished and that there had been no nuclear material or other radioactive material in the building. Iran said the cause was not yet known, adding there were no injuries or radioactive contamination," IAEA reiterated in its statement.
Furthermore, the global nuclear watchdog tweeted on Thursday evening that it was "aware of the reported incident" in Natanz.
IAEA "is in contact with the relevant safeguards authorities in Iran to confirm that the agency can continue all its safeguards verification activities at the uranium enrichment facility" the tweet asserted.
Earlier, the Atomic Energy Organization of Iran (AEOI) had shared an image of the damaged building, which appeared to show a charred roof, broken doors, and blown-out windows.
Part of Iran's nuclear facilities in the city of Natanz was damaged in an explosion or fire in early Thursday, July 2. The Islamic Republic Supreme National Security Council says the cause of the accident has been determined, but for "security reasons" it would not be revealed for the moment.
"The Natanz site is under IAEA safeguards, including both safeguards verification and JCPOA verification and monitoring," the U.N. nuclear watchdog said.
IAEA was referring to the Joint Comprehensive Plan of Action, JCPOA, or Tehran's 2015 nuclear deal with world powers, Britain, China, France, Russia, and the U.S., as well as Germany.
After four times extending the deal by Barak Obama and Donald Trump's administrations, the White House withdrew from the JCPOA in May 2018.
After the incident, the spokesman for the Atomic Energy Organization of Iran (AEOI), Behrouz Kamalvandi, said there were "no nuclear and radioactive contaminating material" at the shed. The "rumors" about the "contamination" were "absolutely untrue," the spokesman insisted.
At the same time, the head of the Islamic Republic Civilian Defense cautioned that Tehran would retaliate against any country that carries out cyberattacks on its nuclear sites.
Three Iranian officials who spoke to Reuters on condition of anonymity said they believed the fire was the result of a cyberattack but did not cite any evidence.
One of the officials said the attack had targeted a centrifuge assembly building, referring to the delicate cylindrical machines that enrich uranium, and said Iran's enemies had carried out similar acts in the past.
Two of the officials said Israel could have been behind the Natanz incident but offered no evidence.
Asked on Thursday evening about recent incidents reported at strategic Iranian sites, Israeli Prime Minister Benjamin Netanyahu told reporters, "Clearly, we can't get into that."
The Israeli military and Netanyahu's office, which oversees Israel's foreign intelligence service Mossad, did not immediately respond to Reuters queries on Friday.
In 2010, the Stuxnet computer virus, which is widely believed to have been developed by the United States and Israel, was discovered after it was used to attack the Natanz facility.