The United States attacked Iran with six B-2 bombers, dropping 12 GBU-57 bunker busting bombs, Sky News reported, citing information in US media.
The US hit the nuclear bunker in Fordow with bombs designed specifically for this purpose. The Fordow complex is located south of Tehran.
Most of the Fordow complex is located deep underground.
Then US Navy submarines fired 30 cruise missiles at Natanz and Isfahan - two other key nuclear sites. A B-2 bomber also reportedly dropped two bunker-busting bombs on Natanz, the NYT reported, citing an official. Sources said the strikes were the culmination of years of planning.
The three sites are key to Iran's uranium enrichment program. But Fordow is buried deep in the ground, meaning it remains largely out of range of Israeli munitions. The United States, on the other hand, has special (non-nuclear) bombs designed to hit such targets.
Donald Trump announced earlier today that the United States had carried out a "very successful attack" on three Iranian nuclear sites, including Fordow.
The bombing came after B-2 stealth bombers were deployed to Guam earlier yesterday, US sources said. A senior US official told Reuters that B-2 bombers were involved in the strikes on Iran's nuclear facilities. It is not yet clear whether Israeli forces were involved in the bombing, which significantly expanded the scope of the military operation.