The Atomic Energy Organization of Iran said July 2 that a fire had broken out at the Natanz fuel enrichment facility in an "industrial shed." Satellite imagery and photos released by Iran, however, suggest that an explosion occurred at a building involved in the assembly of centrifuges. BBC Persian reported that a previously unknown group calling itself the "Cheetahs of the Homeland" had sent it a message claiming responsibility. BBC Persian also said that the messages were sent to journalists before the Atomic Energy Organization of Iran announced that an incident had occurred.