The deaths of the French troops in Mali resulted from a collision between a 'c' and a 'Cougar' helicopter, according to a statement from the head of the French armed forces.
The statement added that the helicopters had been called in as reinforcement to back up French soldiers Mali.
Thirteen French soldiers were killed in Mali when their helicopters collided at low altitude as they swooped in to support ground forces engaged in an counter-terror operation in Mali, the French army said on Tuesday.
It was the biggest loss of French troops in a single day since an attack in Beirut 36 years ago when 58 soldiers died.
"In all likelihood, it was a collision between these two helicopters at low altitude that caused the accident," the armed forces ministry said. "They were supporting commandos from the Barkhane force who were engaged with armed terrorists," the ministry said in a statement.
The deaths were announced by the office of French President Emmanuel Macron who expressed his "deep sadness" at the loss.
"The President of the Republic salutes with the greatest respect the memory of these soldiers," the Elysee Palace statement said. "He bows to the grief of their families and their loved ones."
