Iran has blamed Israel for a sabotage attack on one of its underground nuclear facilities.
Iranian officials warned that they would take revenge over the attack, which damaged centrifuges at the Natanz nuclear facility.
A blackout on 9 April was initially blamed on a power failure but officials later said it was an act of “nuclear terrorism”.
“The answer for Natanz is avenging Israel,” said Saeed Khatibzadeh, spokesperson for Iran’s foreign minister.