Seventeen people were killed in two explosions in Iran at a military base west of the capital, Tehran. Twenty three others were wounded.
State TV was told the blasts occurred at 1.30pm on Saturday when munitions were being moved inside a Revolutionary Guards depot.
The BBC reports the blast was heard in central Tehran, 40km away.
MP Hossein Garousi said on a parliamentary website that a large part of an ammunition depot had exploded.
The death toll was earlier reported as 27.
The Revolutionary Guard was set up shortly after the 1979 Iranian revolution. It is now a major military, political and economic force.
The BBC reports there have been occasional unexplained explosions in Iran before.
Eighteen people were killed in a blast at a Revolutionary Guards base in the north-western province of Lorestan in October 2010.