A large explosion has been reported in the Iranian city of Isfahan as the regime issued conflicting reports apparently designed to deny any suggestions of a sabotage attack on its nuclear facilities.
Officials gave varying accounts of a "huge explosion" in the ancient city, which hosts one of Iran's main facilities for refining uranium in its nuclear programme.
While some sources told news agencies there had been a blast on military facilities, others said there had been a fireball at a petrol station.
Residents of the city were independently telling relatives and friends overseas that the city had been shaken by a massive blast in the early afternoon.
Isfahan is home to Iran's largest facility for research and development of ballistic missiles. Multiple reports said the blast did not emanate from the nuclear facility.
Alireza Zakeri, the provincial governor of Isfahan, was quoted as saying that the blast took place during military exercises at a military airbase.