Abbasi-Davani said explosives had been used to cut power lines from the city of Qom to the Fordow underground uranium enrichment plant on Aug. 17.

A day later, he said, IAEA inspectors had asked for an unannounced visit to Fordow.

“Does this visit have any connection to that detonation? Who other than the IAEA inspectors can have access to the complex in such a short time?” Abbasi-Davani told the gathering in Vienna.