At least five people died on Friday in an accident involving two military helicopters in southeastern France, the Defence Ministry said.The crash happened at Carcès lake, north of St. Tropez. Both Gazelle helicopters belonged to the French Army Light Aviation School of Cannet des Maures, the BBC reported. The flying school has 82 aircraft and trains French, German and Spanish helicopter pilots.Rescue teams at the scene, in the Var region, were searching for a sixth person who was aboard one of the helicopters. The circumstances of the crash were still unknown.The Gazelle has been in service with the French military since the 1970s and is used by the French forces in Mali for their anti-terror mission.