An explosion at an Iranian Revolutionary Guard ammunition dump near Tehran Saturday may have been an accident, as authorities claim, and not sabotage by dissident groups, but it nonetheless exposes some serious problems facing the regime, said a leading authority on Iran at a Washington think tank.

At least 17 people, presumed to be Revolutionary Guard soldiers, were killed and many more hospitalized, according to Iran's Fars news agency. A large part of the depot was destroyed, it reported; officials insisted it was an accident caused by moving ammunition and not linked to nuclear testing or missile firing.

Iranian nerves are jittery over fears of an Israeli attack, the possibility of that the uprisings in the Arab world may spread across their borders, sabotage by local dissidents and, as this incident apparently shows, their own ineptitude.

"They've had real problems handling munitions at ammunition dumps, and I would not be surprised this was an accident, although we don't know for sure," said Patrick Clawson, deputy director of the Washington Institute for Near East Policy. "The Revolutionary Guards are not always an impressive military outfit," he said, adding that a lot of things they do are "pretty bad technically and professionally."

While there have been incidents of sabotage in Kurdish and Baluch areas by armed dissident groups, there's been very little in the Tehran area, he added.

He noted that Iran's oil industry has suffered a series of accidents, about once a month, and it is extremely nervous about these events being reported as sabotage instead of what they really are, problems with low standards of maintenance and operation.

Iranians are already nervous about a possible Israeli attack on their nation's nuclear facilities in the wake of a report last week by the International Atomic Energy Agency confirming suspicions that the Islamic Republic is secretly developing nuclear weapons despite its insistent denials.

The explosion occurred at a depot outside Bindganeh village, 25 miles southwest of Tehran.