Iran’s main nuclear enrichment facility, Natanz, was damaged in Israel’s attack on Friday, the Iranian atomic energy agency said.

Axar.az reports, citing CNN, the heavily fortified facility is 150 miles south of the capital Tehran and houses thousands of centrifuges, used to enrich uranium for nuclear energy.

The complex has overground and underground facilities and it’s unclear what was damaged but no casualties were reported, the agency said.

The head of the UN’s nuclear watchdog, Rafael Grossi, said Iranian authorities have confirmed that Natanz was “impacted” but there were no elevated radiation levels.

Grossi told members of the board at the International Atomic Energy Agency that other nuclear facilities in Iran, Isfahan and Fordow, “have not been impacted.”