A military shooting demonstration in southeast France on Sunday left 16 people wounded, including children, when real bullets were used instead of blank ones, officials said.

Four of the wounded were in serious condition, including a 3-year-old child, Bernard Lemaire, chief of the regional administration in Aude, said on France-3 television. Fifteen of the injured were civilians.

A Defense Ministry official said the incident occurred during a demonstration of hostage-freeing techniques at the Laperrine military barracks. The official said investigators will look into why real bullets were used.

No information was immediately available about what kind of weapon was used.

The soldier who fired the shots has been detained, Lemaire said. He said the injuries were likely an accident but that it could have been a "criminal act."

In a statement, President Nicolas Sarkozy expressed his "horror" at Sunday's incident at the base, which houses the 3rd marine infantry parachute regiment.

The injured were taken to nearby hospitals, with the most seriously wounded taken to Toulouse.