"Due to a fire at the military area in the Vladimir region, ammunition stored in a warehouse detonated", the Russian Defense Ministry states in a statement to state news agencies, writes the news agency AFP.
The Ministry further states that the cause of the fire at the facility near the village of Barsovo was that security routines were not followed during work with explosive substances. Four people have been injured.
The Moscow Times reports that one of Russia's largest depots for ammunition and rockets is located in the area.
Unverified video clips spread on social media show the explosion followed by a large mushroom cloud with smoke.
Several smaller surrounding communities have been evacuated.
