The attack was said to have been carried out by a small drone against a manufacturing center used in the production of centrifuges.Iran’s Atomic Energy Agency said on Wednesday that an attack on one of its facilities early in the morning had been foiled, with no casualties or structural damage to the site.The agency’s statement did not reveal the name of the site, but the targeted building was one of Iran’s main manufacturing centers for the production of the centrifuges used at the country’s two nuclear facilities, Fordow and Natanz, according to an Iranian familiar with the attack and to a senior intelligence official.The attack on the facility near the city of Karaj, on the outskirts of Tehran, was carried out by a small quadcopter drone, according to Iranian media and the Iranian familiar with the attack. While no one claimed responsibility for the attack, the centrifuge factory, known as the Iran Centrifuge Technology Company, or TESA, was on a list of targets that Israel presented to the Trump administration early last year. The Israeli government did not comment on the attack on Wednesday.The drone appeared to have taken off from inside Iran, from a location not far from the site, and hit the structure, the person familiar with the attack said. The person did not know what, if any, damage had resulted.If the attack was thwarted, it would be a welcome victory for Iran’s embattled intelligence and security agencies, which have been blamed for failing to stop a series of attacks over the past year, including two acts of sabotage on the Natanz nuclear facility and the assassination of the top nuclear scientist Mohsen Fakhrizadeh.The centrifuge production facility was on a list that Israel presented in early 2020 to President Donald J. Trump and senior administration officials, including Secretary of State Mike Pompeo and Gina Haspel, director of the C.I.A., as possible targets for attack, part of Israel’s wide-ranging campaign against Iran’s nuclear program, according to the senior intelligence official.Among the targets presented at the time, according to the senior intelligence official, were attacks on the uranium enrichment site at Natanz and the assassination of Mr. Fakhrizadeh. Israel assassinated Mr. Fakhrizadeh that November, and struck the Natanz plant the following April, damaging a large number of centrifuges.According to the intelligence official, the campaign against Iran’s nuclear program was carried out with the knowledge and blessing of the Trump administration. While it is still too early to determine if any damage was inflicted on the centrifuge manufacturing plant on Wednesday, it is easy to assess why it would be a top target for anyone seeking to harm the Iranian nuclear program.Hundreds and possibly even more centrifuges were taken out of action in the April attack on Natanz, and the factory targeted on Wednesday had been tasked with replacing those that were destroyed.In addition, the factory also produces Iran’s more advanced and modern centrifuges, which can enrich more uranium in a shorter time. And Iran’s ability to develop, manufacture, assemble and operate such centrifuges, which significantly shorten the time needed to enrich a sufficient quantity for a bomb, is one of the central negotiating points in talks in Vienna about the future of the 2015 nuclear deal.Iran’s Atomic Energy Agency said the details of Wednesday’s attack were under investigation.“Given the precautions taken to protect sites belonging to the atomic nuclear agency, this morning’s attack was foiled before it could damage the building,” the statement said. The agency praised security and intelligence forces for their prevention of threats “aimed at attacking Iran’s peaceful nuclear activities.”Iran’s aviation agency announced a new law on Wednesday requiring all civilian drones, regardless of size and purpose, to be registered on a government website within six months. The registered drones would be issued licenses.The drone attack on Wednesday has similarities to one carried out against a Hezbollah facility in Beirut in August 2019, which destroyed what Israeli officials described as machinery vital to Hezbollah’s precision-missile production efforts.In that attack, tiny armed drones took off from the coastal area of Beirut, and crashed into the facility. The operatives behind the attack, who Hezbollah officials identified as Israelis, withdrew to a submarine that came to pick them up.Israel and Iran have been fighting a shadow war, with clandestine attacks across the region occurring on land, in the air and at sea. More