The incident took place on Saturday west of Timbuktu, one of three northern Malian towns that were recaptured from jihadists by French and Malian forces in 2013 but which is still periodically attacked by Islamist radicals.

"A unit of the Barkhane force was confronted with a suspect vehicle that refused to submit to an inspection," said a statement from the chief of staff's spokesman in Paris, referring to the 4,500-strong French mission helping Mali and surrounding countries fight jihadists.

"After several warning shots by the French soldiers, which the vehicle failed to obey, a shot was fired to stop the vehicle which was heading towards the French troops," the statement said.

The vehicle, which was carrying a "large" quantity of fuel burst into flames, killing a teenager and two adults who were inside.

An investigation into the incident was under way, it said.

The Coordination of Azawad Movements (CMA) which brings together Tuareg and Arab groups urged the French and Malian governments to investigate the incident which it dubbed "yet another foul up."

In a video seen by AFP, a local leader identified as Mohamed Ali Ag Matahel accused the French troops of a "criminal act" and demanded that "justice be done."

Six years after the successful rout of three extremist groups that had seized Mali's desert north, the jihadist threat continues to plague one of the world's poorest nations and has also spread to several other countries in West Africa.