The French government has launched an investigation into how live rounds that injured 17 people were used during a military display in southern France.  From Paris, Lisa Bryant reports the incident may have been an accident.

The shooting took place during a mock hostage-rescue operation in southern France.  Visitors were watching the exercise.  Fifteen civilians, including five children, were wounded after live rounds - rather than blank cartridges - were fired.  Two soldiers were also injured.  Those wounded were described as being in stable condition.

French President Nicolas Sarkozy, who visited some of the wounded, vowed swift and tough punishment against those responsible for the incident, which he described as unacceptable negligence.

Investigators are now looking into the cause of the incident.  A senior military official told the Agence France-Presse news agency it was probably due to an accident.  But in an interview on France-Info radio, Defense Minister Herve Morin ruled nothing out.

Morin said it was too early to say whether the shooting was due to an accident or a willful act.  But it was certain that mistakes were made. Ordinarily, he said, an experienced soldier would be able to distinguish blank cartridges from real bullets.  Normal safety procedures should also have prevented such an incident.

The sergeant who apparently fired the rounds was considered to have an excellent military record, and had not had any history of psychological or other problems.  He fired the real bullets after a previous exercise in which he had fired fake ones.  He was detained, along with three other soldiers.