The Iranian military is claiming just 17 killed after reporting a higher fatality rate earlier. However, other sources put the death toll higher.
Two hours after the explosion a fire still raged and there were traffic jams on nearby roads, a local reporter said.
The death toll was revised down from an earlier figure released by the Revolutionary Guards of 27.
Israeli DebkaFile is reporting 32 killed, including a General in the Revolutionary Guard. Hassan Moghadan was at the head of some of the Islamic Republic's nuclear weapons research.
Debka is claiming that there were two explosions on two bases and that they may have occurred as Iran was fitting a nuclear warhead to a missile:
Our sources report increasing evidence that the first explosion was caused by a failed effort to mount a nuclear warhead on a Shahab-3 intermediate-range missile.