The accidental blasts took place in an IRGC base in Bidganeh village in the northern province of Alborz, some 35 km from Tehran.
Windows of buildings near the site were shattered. Tehran's residents felt the shock caused by the explosions.
Brigadier General Hassan Moqaddam, a senior commander of the IRGC, was among the dead.
According to IRGC's public relations chief General Ramezan Sharif, 16 more were injured, some critically.
The blasts happened during relocation of some ammunition inside the base, Sharif said.
Iranian lawmaker Hossein Garousi said the explosions were so huge that the sound caused panic among the residents of Qods and Shahryar cities, several kilometers away.
The IRGC is a branch of Iran's military founded after the Iranian revolution 33 years ago.
The IRGC has 125,000 military personnel, including ground, air and naval forces. It also controls the paramilitary Basij militia, which has 90,000 personnel.
Deccan Herald is on WhatsApp Channels | Join now for Breaking News & Editor's Picks