A soldier wounded 16 people including a three-year-old child accidentally firing live bullets at a French military show.
Four of the wounded were in serious condition.
The incident happened yesterday during a demonstration of hostage-freeing techniques at a military barracks in the city of Carcassonne.
The official said investigators would look into why real bullets were used.
The soldier who fired the shots was detained.
An army spokesman said the shooting was probably an accident but that it could have been a “criminal act”.
President Nicolas Sarkozy expressed “horror” at the shooting at the base, which houses the parachute regiment of the Third Marine Infantry.
The wounded were taken to local hospitals, with the most serious cases taken to Toulouse.