Updated

An explosion at a Revolutionary Guard ammunition depot west of Tehran Saturday killed at least 17 soldiers, including a senior commander of the powerful military force, Iranian officials said.

Guard spokesman Gen. Ramazan Sharif said the blast occurred as the result of an accident during the transport of munitions at the base. The site is located outside Bidganeh village, 25 miles southwest of the capital.

"My colleagues at the Guard were transporting ammunition at one of the depots at the site when an explosion occurred as a result of an accident," Sharif said

At least 17 Guard members were killed, state TV reported. The broadcast said 16 other soldiers were injured and hospitalized. Sharif said some of them were in critical condition.

Earlier, Sharif had said that 27 soldiers were killed but later retracted his statement, explaining that the error was due to an illegible fax from officials at the site of the blast. Among those killed was Hasan Moghaddam, a senior Guard commander.

While the explosion occurred during a time of heightened tension between Israel, the U.S. and other Western powers, Iranian lawmaker Parviz Soroori ruled out sabotage.

"No sabotage was involved in this incident. It has nothing to do with politics," Soroori was quoted as saying by the parliament's website, icana.ir.

An exiled Iranian dissident group, the Mujahedin-e Khalq or MEK, meanwhile claimed that the blast hit a missile base run by the Revolutionary guard rather than an ammunition depot.

Former MEK spokesman Alireza Jafarzadeh, citing what he called reliable sources inside Iran, said that the explosion hit the Modarres Garrison of the Islamic Revolutionary Guard Corps west of Tehran.

Jafarzadeh said in an email that the Modarres Garrison belongs to the IGRC's missile unit and the blasts "resulted from the explosion of IRGC missiles." He did not say what he believes triggered the explosion.

The MEK in the past has disclosed the sites of several key Iranian nuclear installations as well as details of their operations, although their reports have not always been reliable.

The MEK fought the Tehran regime on the side of Iraq's Saddam Hussein and is listed as a terrorist organization by the State Department. But the group says it has renounced violence and some former senior government officials and members of Congress are calling for the Obama administration to remove the group from the list.

The blast comes just days after a new report by the U.N.'s nuclear watchdog agency that Iran is conducting nuclear weapons-related research and follows unconfirmed reports that Israel was considering a military strike on Tehran's nuclear program.

In the past, Tehran has accused the West of engaging in a campaign of sabotage and assassination against the regime.