A Foreign Legion drill instructor has been suspended after an "imbecilic" shooting exercise triggered a huge wildfire that threatened the outskirts of Marseille, France.

No one was killed as the blaze ripped through 2,718 acres of brush and damaged homes in the suburbs of the French city.

But one fireman suffered burns and four rescuers were treated for smoke inhalation.

The fire erupted after troops from the 1st Foreign Legion Regiment used tracer rounds, which contain an incendiary substance to make them visible in flight, during a practice session at their base.

At dawn, firefighters said the blaze was under control, but this did little to calm the anger of local officials.

Local prefect Michel Sappin, the French government's senior regional official and police chief, criticized the "imbecilic" actions of the military.

The fire, started at a camp in Carpiagne, was the worst to hit southern France in three years.

Marseille's mayor and senator Jean-Claude Gaudin demanded that the military help out with the clean-up operation.

"We did the best we can but, when you're faced with this kind of incredible stupidity, you need to say so with a certain force," he added.

The military accepted responsibility for the fire.

"It was found that tracer rounds were used in violation of orders given… the army general staff has taken an interim decision to suspend the leader responsible from his duties," Colonel Benoit Royal said.

Thick black smoke swirled around the area, as nearly 500 firefighters — backed up by water dropping planes - tackled the blaze.

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