The explosion occurred on Tuesday afternoon while soldiers were unloading ammunition from a tank into a truck. Seven people died instantly and six others were injured, two of them died in hospital later that day.
Four servicemen are still being treated in hospital. No information on their condition is available so far.
Military prosecutors have launched a probe into the incident.
Russian Defense Minister Anatoly Serdyukov has sent a special commission to the North Caucasus Military District.
On Tuesday Russia began the active stage of large-scale military exercises in several regions of the Southern Federal District, which includes the highly volatile North Caucasus republics. The exercise, dubbed Caucasus Frontier 2008, involves some 8,000 military personnel, about 700 combat vehicles and over 30 aircraft.