Iranian media say 18 people were killed and 14 others wounded in an explosion at a military base in the country's western Lorestan Province.
The state IRNA news agency reported that the casualties were all members of the Islamic Revolutionary Guards Corps (IRGC).
But the semiofficial Fars news agency quoted a commander of the elite force, Yadollah Bouali, as saying that some of the casualties were workers at the base. He did not specify whether they included members of the Guards.
The injured were taken to the provincial capital of Khoramabad, some 500 kilometers southwest of Tehran.
IRNA reported that the cause of the blast was a fire that had reached the ammunition storage area at the Imam Ali base.
There was no word on what ignited the blaze.
An initial report
by Fars put the death toll at "several" guards.
Khoramabad is geographically close to northwestern border areas which have witnessed several attacks in recent months by ethnic Kurds disgruntled with the central government.
Iranian authorities have blamed Kurdish separatists for a blast at a military parade in the northwestern town of Mahabad that killed 12 people in September.
The Islamic Revolutionary Guards Corps, set up after the 1979 Islamic Revolution to defend the regime, has become a major military, political, and economic force in Iran.
Corps members were heavily involved in the government's crackdown on opposition protests after last's year disputed election results that gave President Mahmud Ahmadinejad a second term in office.
The force and its economic interests have been targeted by United Nations sanctions imposed on Iran for pursuing its controversial nuclear program.compiled from agency reports