According to state television, an incident at Iran's Natanz nuclear facility on Sunday was triggered by "nuclear terrorism," according to the country's nuclear leader Ali Akbar Salehi, who also said that Tehran reserves the right to take action against the perpetrators.

Israel's Kan public radio station quoted unnamed intelligence sources as saying that Israel's Mossad security agency had carried out a cyberattack on the site.

According to Iranian newspapers, a problem with the electrical distribution system of the Natanz site triggered an incident earlier on Sunday, according to a spokesperson for Iran's Atomic Energy Organisation (AEOI).

Behrouz Kamalvandi, the spokesperson, said there were no injuries or contamination as a result of the incident. Kamalvandi "suffered a fractured head and leg" in an accident while visiting the Natanz site, according to Iranian media. The accident's cause was not stated in the papers.

The plant, which is situated in the desert in the central province of Isfahan, in the heart of Iran's uranium enrichment program and is inspected by inspectors from the United Nations' nuclear watchdog.

“While condemning this heinous act, Iran stresses the importance of the international community and the International Atomic Energy Agency dealing with this nuclear terrorism, and reserves the right to take action against the perpetrators,” Salehi said. He didn't go into detail.

Israel, which has accused Iran of attempting to develop nuclear weapons capable of being used against it, has made no official statement in response to the incident. It happened a day after Iran, which has denied seeking nuclear weapons, began operating new advanced enrichment centrifuges at Natanz.

“We are aware of the media reports,” an IAEA spokesperson said via email when asked about what had happened. At this time, we have no comment.”

According to Kan Radio, the damage at Natanz was more severe than had been recorded in Iran, citing intelligence sources.

Prime Minister Benjamin Netanyahu made no mention of Natanz during a ceremony on Sunday with Israeli military and intelligence chiefs commemorating Israel's 73rd anniversary next week.

“The war against Iran's nuclearization... is a monumental task,” he said.

Tehran claims that its nuclear program is for peaceful purposes only.

VIRUS AND FIRE

A fire broke out at the facility in July of last year, which Iran claimed was an effort to sabotage the country's nuclear program.

After being used to target Natanz in 2010, the Stuxnet computer virus, widely believed to have been created by the US and Israel, was discovered.

The incident at the Natanz facility comes amid attempts by Tehran and Washington to resurrect Iran's 2015 nuclear agreement with major powers, which was scrapped three years ago by former US President Donald Trump. Trump reimposed sanctions on Iran that had been suspended as part of the agreement, as well as imposing a slew of new ones.

The White House and State Department in Washington did not respond to news of the attack.

Iran has steadily broken many of the accord's constraints in response to US sanctions. At last week's indirect talks in Vienna, the two countries set out tough positions on how to get them back into full compliance with the agreement.

“The action taken against the Natanz site demonstrates the opposition to Iran's industrial and political progress's inability to prevent Iran's nuclear industry from developing significantly,” Salehi said.

“To thwart the aims of those who directed this terrorist act,” he said, “Iran will continue to upgrade its nuclear technology on the one side while lifting oppressive US sanctions on the other.”

Iran has blamed Israel for the assassination of Mohsen Fakhrizadeh, who was seen as the mastermind of a clandestine Iranian nuclear weapons program by Western intelligence services last year.

Israel has not verified nor denied its involvement in the murder.

On Saturday, President Hassan Rouhani reaffirmed Iran's commitment to nonproliferation while overseeing the launch of advanced centrifuges at the Natanz plant to commemorate the country's National Nuclear Technology Day.