Iranian officials acknowledged that an explosion at the Natanz nuclear complex caused significant damage and set the country's nuclear program back by months. The explosion took place at a warehouse where advanced centrifuges are assembled, according to a spokesman for the Atomic Energy Organization of Iran. The spokesman said that the warehouse held "advanced equipment and precision measurement devices" that were "either destroyed or damaged," which may "slow down the development and expansion of advanced centrifuges." A Middle Eastern intelligence officer and a member of the Islamic Revolutionary Guard Corps (IRGC) asserted that the explosion was caused by a bomb. Israel may be responsible for the attack; Israeli officials neither confirmed nor denied involvement.