The facts - and questions Where did the US strikes hit and did they succeed?

The Atomic Energy Organization of Iran (AEOI) confirmed that attacks took place on its Fordow, Isfahan and Natanz sites, but said its nuclear programme would not be stopped.

- Peter Beaumont

What was the target? Iran and the UN nuclear watchdog said there were no immediate signs of radioactive contamination around the three locations after the strikes.

The Iranian Red Crescent Society reported no deaths from the US strikes, appearing to confirm Iranian claims they had been largely evacuated. The health ministry said those who were injured showed no evidence of nuclear contamination. The Pentagon said a battle damage assessment was being conducted.

What do we know about the strike on Fordow?

Long regarded as the most difficult military target among Iran's nuclear sites, the uranium enrichment facilities at Fordow - the primary target of the operation - are buried beneath the Zagros mountains. Reports have suggested that the site was constructed beneath 45-90 metres of bedrock, largely limestone and dolomite.

Some experts have suggested the layering of the sedimentary rocks, including faults, would also make it more difficult to strike the centrifuge array, providing a kind of geological cushioning.