During its attack on Iran on October 25, Israel destroyed the Parchin military facility, about 30 kilometers from Tehran, claiming that “top secret research activities on nuclear weapons” had been carried out there in the past year, according to three current and former American and Israeli officials, quoted in a report by journalist Barak Ravid on the American “Axios” and Israeli “Walla” websites today, Friday.

American and Israeli officials said the attack was a direct attack on Iranian efforts in the past year to resume research into nuclear weapons.

The former Israeli official who was briefed on the attack said that a sophisticated technological device used in designing the explosive material that encases uranium in a nuclear facility and is necessary to carry out a nuclear explosion was destroyed.

One of the targets of the attack in Iran was the Taleqan 2 facility inside the Parchin facility. The Institute for Science and International Security published a clear image after the Israeli attack, showing that the Taleqan 2 facility was completely destroyed.

According to Israeli and American officials, the activities at the facility were part of moves by Iranian government officials to conduct research activities that could be used to develop a nuclear weapon, but could also be presented as necessary for civilian purposes.

"They did scientific work that could be put on the ground to make a nuclear weapon," a U.S. official said. "This was top secret. A small part of the Iranian government knew about it, but most of the Iranian government didn't."

Israeli and American intelligence spotted the “suspicious activity” earlier this year. Iranian scientists at the facility carried out computer modeling, metallurgy research and research into explosives that could be used to develop a nuclear weapon.

White House officials warned the Iranians, during direct talks last June, against continuing “suspicious research activities.”

An American official said that in the months preceding the Israeli attack, there was concern about these Iranian activities, and that this concern prompted the American Director of National Intelligence to change his assessment of the Iranian nuclear program, according to which Iran is not developing a nuclear weapon.

Israel has placed this facility among its targets for attack, although US President Joe Biden has asked Israeli Prime Minister Benjamin Netanyahu not to attack nuclear facilities in order to prevent a war with Iran.

The report indicated that the "Talaqan 2" facility was not part of the declared Iranian nuclear program, and therefore Iran could not acknowledge its existence.

"The attack was a not-so-subtle message to Iran that Israel has significant access to what's going on inside the Iranian security establishment, even when these are secret matters and are known to a very small group of people in the Iranian government," a US official said.