What is known about the three nuclear facilities targeted by the US: CNN

The US has struck three main Iranian nuclear facilities, US President Donald Trump announced on Truth Social on Saturday evening. The facilities are Fordow, Isfahan, and Natanz, which are at the core of Iran's nuclear ambitions.

Here is what we know about the three facilities:

Natanz: The nuclear complex, located about 250 kilometers (150 miles) south of the capital Tehran, is considered Iran's largest uranium enrichment facility.

Analysts say it is used for the development and assembly of centrifuges for uranium enrichment, a key technology that turns uranium into nuclear fuel.

According to the non-profit organization Nuclear Threat Initiative (NTI), Natanz has six above-ground buildings and three underground structures, two of which can house 50,000 centrifuges.

According to the International Atomic Energy Agency (IAEA), Iran was enriching uranium to 60% purity at its above-ground pilot fuel enrichment plant. Weapons-grade uranium is enriched to 90%.

Fordow: Much is still unknown about the full size and nature of this facility, which is located near the holy city of Qom and buried deep within a mountain range. Much of what we know comes from an archive of Iranian documents stolen by Israeli intelligence years ago.

The main halls are located about 80 to 90 meters (around 262 to 295 feet) underground. The US is the only country with the type of bomb needed to strike at such a depth, Israeli officials and independent reports have previously stated.

Recent IAEA reports indicated that Iran had increased its production of uranium enriched up to 60% at Fordow. According to experts and the IAEA, the facility now contains 2,700 centrifuges.

Isfahan: Isfahan is located in central Iran and is home to the country's largest nuclear research complex.

According to the NTI, the facility was built with Chinese assistance and opened in 1984. The NTI states that 3,000 scientists work in Isfahan, and the site is "suspected of being the center of Iran's nuclear weapons program."

It "operates three small research reactors supplied by China," as well as a "conversion plant, a fuel production plant, a zirconium cladding plant, and other facilities and laboratories," says the NTI.