The fire broke out around in the early afternoon in the Lozere region, about 140 kilometres northwest of Montpellier.
Officials said it might have been sparked by a vehicle catching fire on a local road.
By late afternoon, the fire had burned some 153 hectares and continued to spread.
Around 270 firefighters from Lozere and neighbouring departments were deployed, backed by four Canadair water bombers and two Dash aircraft.
A Lozere fire service spokesman said their combined efforts had helped “contain the blaze and save two homes” that were directly threatened.
“The flanks are being held. Work is now focused on the head of the fire, which remains inaccessible,” he added.
As a precaution, two hamlets in the municipality of La Tieule, directly in the path of the flames, were evacuated in the late afternoon, affecting about 20 homes.
“This is an area with a great deal of woodland. It’s extremely dry. The drought is unlike anything we’ve seen in a long time,” said Marc Toulouse, a senior fire officer in Lozere.
Local authorities urged residents against calling emergency services to report the blaze, warning that doing so could overload crews already fighting the fire.
French officials are still taking stock of the damage caused by a series of fires, mainly in the south of France, including largest wildfire since 1949, in the south-west Gironde region. (AFP)
