The International Atomic Energy Agency said Tuesday it believes Israeli airstrikes on Iran’s Natanz enrichment site have had “direct impacts” on the facility’s underground centrifuge halls.

The strikes are part of an air campaign Israel launched against its longtime foe five days ago, targeting Iran’s military and nuclear program.

This marks the first time the United Nations’ nuclear watchdog has assessed damage from the strikes in the underground parts of Natanz, which is the main enrichment facility of Iran’s nuclear program.

“Based on continued analysis of high-resolution satellite imagery collected after Friday’s attacks, the IAEA has identified additional elements that indicate direct impacts on the underground enrichment halls at Natanz,” the agency said.

Already, an above-ground enrichment hall had been destroyed, as well as electrical equipment that powered the facility.