"21 persons injured by the blast have been brought to the hospital. They are in grave condition," Shirvan city central hospital reported.
Later, local media reported two killed citing the Azerbaijani Defense Ministry.
The explosion was caused by a spark in 146 out of 1,500 tons of ordnance ordered by the Ministry of Defense for disposal. According to local residents, the violent explosions, heard even in the city, continue.
The plant owned by the Azerbaijan's Ministry of Defense Industry produces ammunition.