Firefighters battling France's worst wildfire of the summer fear changing winds over the weekend could make it harder to battle the blaze that has already burned for four days and killed two people.
"We're expecting risky days ahead," said Florent Dossetti of the Var department fire brigade.
But he added that there had been fewer flareups Thursday than the day before, with firefighting planes and helicopters dumping water on new blazes to aid colleagues on the ground.
Around 1,200 firefighters and 250 fire engines worked through the night to tamp down the flames along an 80-kilometre front, the Var prefecture said.
It added that the situation "remains very unstable" in parts of the affected area, with 7,100 hectares of forest already burned.
Flames have ripped through the arid Plaine des Maures nature reserve towards the glitzy Riviera resort of Saint-Tropez.
Cigarette butts found
Firefighters have appealed for information about how the fire began, with current theories suggesting it started at a motorway rest stop on Monday where cigarette butts were found.
The national federation of firefighters (FNSPF) has also called for much higher fines to be applied for "careless" disposal of cigarette butts in public places. It currently stands at 135 euros, but the President of the organisation, Grégory Allione says fines should be graded to take into consideration the overall cost of a fire which can reach millions of euros.
Around 10,000 residents and holidaymakers have been evacuated in the southern French department, with only a fraction able to return to campsites late Wednesday while others remained in emergency accommodation.
The prefecture urged evacuees to "above all avoid returning to your home or the place you were holidaying".
Beyond the human impact, local producers of rosé wine fear an economic blow from destroyed vines, while an operation to save protected local tortoises has been under way in the Maures nature reserve.
The region has long faced seasonal wildfires linked to the dry and hot summer weather, but climate scientists warn they will become increasingly common because of man-made global warming.