President Donald Trump’s decision to order U.S. forces to attack three key Iranian nuclear installations may have sabotaged the Islamic Republic’s known atomic capabilities, but it’s also created a monumental new challenge to work out what’s left and where.

Trump said heavily fortified sites were “totally obliterated” late Saturday, but independent analysis has yet to verify that claim. Rather than yielding a quick win, the strikes have complicated the task of tracking uranium and ensuring Iran doesn’t build a weapon, according to three people who follow the country’s nuclear program.

International Atomic Energy Agency monitors remain in Iran and were inspecting more than one site a day before Israel started the bombing campaign on June 13. They are still trying to assess the extent of damage, and while military action might be able to destroy Iran’s declared facilities, it also provides an incentive for Iran to take its program underground.

Trump dispatched B-2 stealth jets laden with Massive Ordnance Penetrators, known as GBU-57 bombs, to attempt to destroy Iran’s underground uranium-enrichment sites in Natanz and Fordo.

Satellite images taken on Sunday of Fordo and distributed by Maxar Technologies show new craters, possible collapsed tunnel entrances and holes on top of a mountain ridge.

They also show that a large support building on the Fordo site remained undamaged. There were no radiation releases from the site, the IAEA reported.

New pictures of Natanz show a new crater about 18 feet in diameter. Maxar said in a statement that the new hole was visible in the dirt directly over a part of the underground enrichment facility. The image doesn’t offer conclusive evidence that the attack breached the underground site, buried about 130 feet under ground and reinforced with an 26-foot-thick concrete-and-steel shell.

U.S. Air Force General Dan Caine told a news conference earlier on Sunday that an assessment of “final battle damage will take some time.” IAEA inspectors, meanwhile, haven’t been able to verify the location of the Persian Gulf country’s stockpile of near-bomb-grade uranium for more than a week. Iranian officials acknowledged breaking IAEA seals and moving it to an undisclosed location.

Israeli damage

Before the U.S. intervention, images showed Israeli forces alone had met with limited success four days after the bombing began. Damage to the central facility in Natanz, located 186 miles south of Tehran, was primarily limited to electricity switch yards and transformers.

The U.S. also joined in attacking the Isfahan Nuclear Technology and Research Center, located about 279 miles south of Tehran. That was after the IAEA reassessed the level of damage Israel had dealt to the facility. Based on satellite images and communications with Iranian counterparts, Isfahan appeared “extensively damaged,” the agency wrote late on Saturday.

Images now show extensive new damage after the U.S. bombing, including to a large cluster of industrial buildings identified by Bloomberg last week. The IAEA reported earlier that the destruction may result in “radioactive and chemical contamination within the facilities that were hit.”

Missing uranium

The IAEA’s central mission is to account for gram-levels of uranium around the world and to ensure it isn’t used for nuclear weapons. The latest bombing now complicates tracking Iranian uranium even further, said Tariq Rauf, the former head of the IAEA’s nuclear-verification policy.

“It will now be very difficult for the IAEA to establish a material balance for the nearly 9,000 kilograms of enriched uranium, especially the nearly 410 kilograms of 60% enriched uranium,” he said.

Last week, inspectors had already acknowledged they’d lost track of the location of Iran’s highly enriched uranium stockpile because Israel’s ongoing military assaults are preventing its inspectors from doing their work.

That uranium inventory — enough to make 10 nuclear warheads at a clandestine location — was seen at Isfahan by IAEA inspectors. But the material, which could fit in as few as 16 small containers, may have already been spirited off site.