Iran”s Natanz nuclear site lost power on Sunday just hours after starting up advanced new facilities to speed up the enrichment of uranium.
Announcing an “incident” on state TV, a spokesman for the country’s nuclear programme said no injuries or contamination had occurred.
Power at Natanz had been cut across the facility, comprised of above-ground workshops and underground enrichment halls, Behrouz Kamalvandi told Iranian state television.
“We still do not know the reason for this electricity outage and have to look into it further,” Kamalvandi said.
Asked by the state TV correspondent if it was a “technical defect or sabotage,” Kamalvandi declined to comment.
The news came just hours after President Hassan Rouhani inaugurated the new devices at the enrichment plant in a ceremony also broadcast on state television via a live link to engineers, who announced they had started the process.
Israeli media speculated that Sunday’s power outage at the plant was the result of a cyberattack but offered no proof or source.
Natanz suffered a mysterious explosion in July that authorities later described as sabotage.
Israel, Iran’s regional archenemy, has been suspected of carrying out an attack there, as well as launching other assaults.
This latest incident comes as negotiations continue with world powers in Vienna to bring the United States back into the nuclear deal that Donald Trump withdrew from in 2018.
His successor Joe Biden has said he is ready to return, claiming the accord had been successful in dramatically scaling back Iran’s nuclear activities.
Israel and Western nations fear that Iran is trying to develop nuclear weapons.