Satellite imagery captured ahead of U.S. strikes on three major Iranian nuclear sites showed "unusual" movement around the entrance to Iran's Fordow enrichment facility.

Pictures taken on Thursday and Friday showed "unusual truck and vehicular activity" close to the entrance of the underground Fordow complex south of Tehran, satellite imagery firm Maxar said late on Saturday.

Why It Matters

U.S. President Donald Trump on Saturday announced U.S. strikes on Fordow, a complex built deep into a mountain roughly 60 miles from the capital, as well as attacks on the nuclear sites of Natanz and Isfahan in central Iran. Tehran had warned of "irreparable damage" to the U.S. if Washington became directly involved in the Middle East conflict.

Iran says its nuclear program is peaceful, but international observers believe the country has enriched uranium far beyond what is needed for non-nuclear use. Israel, the U.S. and other American allies have consistently said they would not tolerate Tehran gaining a nuclear weapon.

Satellite imagery captured by Maxar on June 19 showing cargo trucks close to the underground entrance of the Fordow fuel enrichment facility, prior to U.S. airstrikes on the underground complex. Satellite imagery captured by Maxar on June 19 showing cargo trucks close to the underground entrance of the Fordow fuel enrichment facility, prior to U.S. airstrikes on the underground complex. Satellite image ©2025 Maxar Technologies What To Know

A total of 16 cargo trucks were spotted on the access road leading up to the Fordow tunnel entrance on Thursday, but most had moved to a spot 1 kilometer (0.6 miles) northwest of the access road by the following day, Maxar said.

New trucks and multiple bulldozers had appeared close to the main entrance by Friday, with one truck very close to the main tunnel entrance, the satellite imagery provider said.

The significance of the activity is not yet clear, but Iranian state media reported key nuclear sites had been evacuated ahead of U.S. attacks, with enriched uranium moved "to a safe location."

Iran was producing considerable amounts of highly enriched uranium at Fordow, but it is not immediately apparent how much was still at the site in recent days, William Alberque, a senior adjunct fellow at the Pacific Forum and a former director of NATO's Arms Control, Disarmament and WMD [Weapons of Mass Destruction] Non-Proliferation Center, told Newsweek.

Trump said on Saturday evening the U.S.' "massive precision strikes" were a "spectacular military success," adding: "Iran's key nuclear enrichment facilities have been completely and totally obliterated."

Experts said it would likely take several of American GBU-57/B bombs—weighing in at a massive 30,000 pounds—to take out more than just the entrance to Fordow. An unnamed U.S. official told Reuters that B-2s were involved in the strikes, while the U.S. hit Natanz and Isfahan with Tomahawk submarine-launched cruise missiles, two senior Pentagon officials told CBS News.

Satellite imagery showing trucks and multiple bulldozers close to the entrance of Fordow underground facility in central Iran on June 20, one day before the U.S. launched airstrikes on the site. Satellite imagery showing trucks and multiple bulldozers close to the entrance of Fordow underground facility in central Iran on June 20, one day before the U.S. launched airstrikes on the site. Satellite image ©2025 Maxar Technologies

"A full payload of BOMBS was dropped on the primary site, Fordow," Trump said in a separate post to Truth Social. Fox News host, Sean Hannity, said the U.S. had used six GBU-57B bombs, also known as Massive Ordnance Penetrator bombs, citing a conversation with the president.

"The nature of the facility at Fordow—under a mountain—means that the success of the operation is not immediately apparent," said Matthew Savill, the director of military sciences at the influential British think tank the Royal United Services Institute (RUSI).

Israel's president, Isaac Herzog, told the BBC on Sunday that Iran's nuclear program "has been hit substantially," but did not provide details on the exact damage to the sites.

The United Nations' nuclear watchdog, the International Atomic Energy Agency (IAEA) said on Sunday it had not detected any increase in off-site radiation after the strikes on the three sites.

Manan Raeisi, an Iranian lawmaker in the city of Qom, close to the site, told the country's semi-official Tasnim news agency that "critical infrastructure remains intact" at Fordow.

"What was hit was mostly on the ground and fully restorable," Raeisi said. "Trump's bluff about destroying Fordow is laughable."

Israel had launched strikes on Iran's nuclear facilities and scientists, as well as the country's ballistic missile sites and other military assets, late on June 12. Iran responded with drone and missile barrages.

Israel targeted Natanz and Isfahan, but analysts said only the U.S.'s B-2 heavy stealth bombers and GBU-57/Bs could successfully take out Fordow.

Fordow's existence was secret until 2009.

What People Are Saying

Iran's foreign minister, Abbas Araghchi, said on Sunday: "The events this morning are outrageous and will have everlasting consequences."

"I am gravely alarmed by the use of force by the United States against Iran today," U.N. Secretary-General António Guterres said on Saturday. "This is a dangerous escalation in a region already on the edge—and a direct threat to international peace and security."

What Happens Next

Trump said on Saturday that any Iranian retaliation against the U.S. would bring fresh American attacks "GREATER THAN WHAT WAS WITNESSED TONIGHT."