Iran charged Monday that its arch-enemy Israel was behind an attack on its Natanz uranium enrichment plant and vowed it would take "revenge" and ramp up its nuclear activities.
The Atomic Energy Organization of Iran (AEOI) said a "small explosion" had hit the plant's electricity distribution centre Sunday in what the foreign ministry called an Israeli act of "terrorism".
The latest of a string of incidents hitting Iran's nuclear programme came days after talks resumed in Vienna to salvage the battered 2015 Iranian nuclear deal that former US president Donald Trump abandoned.
His successor Joe Biden wants to revive the accord between Iran and six world powers, which places limits on Tehran's nuclear programme in return for relief from punishing economic sanctions.
Israel strongly opposes the nuclear deal and has vowed to stop Iran from building an atomic bomb -- a goal Tehran has always denied pursuing.
Iran initially reported a power blackout had hit the Natanz site Sunday, a day after it announced it had started up advanced uranium enrichment centrifuges banned under the deal.
Israel did not claim responsibility for the incident, but unsourced media reports in the country attributed it to the Israeli security services carrying out a "cyber operation".
The New York Times, quoting unnamed US and Israeli intelligence officials, also said there had been "an Israeli role" in the attack in which an explosion had "completely destroyed" the power system that fed the site's "underground centrifuges".
The White House Monday said the US "was not involved in any manner", in the attack.
"We have nothing to add on speculation about the causes or the impacts," Press Secretary Jen Psaki told reporters.
- Israeli 'terrorism' -
Israeli Prime Minister Benjamin Netanyahu, while hosting US Secretary of Defense Lloyd Austin in Jerusalem, reiterated his stance that Israel will prevent Iran from obtaining a nuclear weapon, without mentioning the Natanz incident.
"I will never allow Iran to obtain the nuclear capability to carry out its genocidal goal of eliminating Israel, and Israel will continue to defend itself against Iran's aggression and terrorism," he said Monday.
Iranian foreign ministry spokesman Khatibzadeh vowed that Iran's response to the Natanz incident would be to take "revenge on the Zionist regime" when and where Tehran chooses.
"Of course the Zionist regime, with this action, tried to take revenge on the people of Iran for their patience and wise attitude regarding the lifting of sanctions."
AEOI head Ali Akbar Salehi said "this incident was certainly sabotage", state news agency IRNA reported.
In a separate report, Fars news agency quoted Salehi as saying "the damaged centrifuges will be replaced with even more powerful" ones.
In a related incident, AEOI spokesman Behrouz Kamalvandi had an accident Sunday while inspecting the site when he "fell from a few meters and suffered light fractures on his feet and head", IRNA reported.
Kamalvandi gave a video interview from his hospital bed Monday to the Tasnim news agency in which he voiced confidence that after the "small explosion... they can quickly repair the damaged areas".
- Avoiding 'trap' -
Tehran has blamed Israel for previous attacks on its nuclear facilities and experts -- including the killing last November of its top nuclear scientist, Mohsen Fakhrizadeh.
Natanz was the site of a previous incident in July, during which a building was damaged, and some Iranian media also blamed Israel.
Israel and Iran have long fought a shadow war, with Israel often striking Iran-allied forces in war-torn Syria. And since March, both countries have accused each other of a number of maritime attacks.
Iran's Foreign Minister Mohammad Javad Zarif said Tehran would not allow the Natanz attack to affect the Vienna talks. Iran must avoid "falling in the trap" set by Israel, he told parliamentarians.
Russia said it was closely following what it called a "serious incident" and "if it is confirmed that someone's malicious actions are behind this incident, then such intent deserves strong condemnation".
Germany, a partner to the nuclear accord, warned that the "development in Natanz" was "not a positive contribution" to the negotiations.
Qatar denounced "a dangerous act of sabotage that would increase tension and negatively affect the security and stability of the region".
The European Union said it "rejects any attempts" to undermine the Vienna talks and stressed the "need to clarify the facts" over the incident.
Meanwhile, the EU on Monday added eight Iranian security officials, including the chief of the powerful Revolutionary Guards, and three notorious prisons to a sanctions blacklist over a 2019 protest crackdown in the Islamic republic.
Iran responded by declaring it would cease all talks with the bloc on human rights and all "cooperation resulting from these talks... especially in (the fields of) terrorism, drugs and refugees".