Iran's Natanz nuclear facility suffered a power outage that Ali Akbar Salehi, the head of the Atomic Energy Organization of Iran (AEOI), described as "nuclear terrorism" on April 11. Unnamed Israeli and U.S. intelligence officials said that an Israeli-orchestrated explosion had destroyed an internal power system feeding electricity to underground centrifuges at Natanz. The officials said that Iran could need at least nine months to return Natanz's enriched uranium production to previous levels. Behrouz Kamalvandi, an AEOI spokesman, reported that the entire complex had lost power but claimed that there were no casualties or damage. Israel neither confirmed nor denied responsibility for the action.