Seventeen French firefighters have been hurt battling the blazes
Two more of the forest fires that have devastated parts of south-eastern France, killing five people in recent days, have been brought under control.
A fire that has destroyed woodland near the town of La Motte for the past two days is still burning, but is advancing only slowly, firefighters say.
Another that started on Wednesday near Salon-de-Provence was brought under control overnight.
Dry weather and soaring temperatures have led to hundreds of fires throughout Europe, and French firefighters warn that the lull in the south-east could be short-lived.
Near La Motte, in the Var department, helicopters dropped thousands of gallons of water on the fire as around 700 firefighters worked on the ground overnight.
"It is not completely under control, but we have made progress - now everything depends on the wind," a local firefighter said.
Temperatures have remained high on Thursday, and forecasters predict that fierce local winds - known as the "mistral" - could pick up later in the day.
To the west, near Salon-de Provence, 400 firefighters and four planes battled a forest fire which officials say has now been "circumscribed".
However they also warn that the fire could flare up again if the mistral picks up.
Foreign firefighters - from Italy and Russia - have been helping their French colleagues while Greece and Norway have offered to send firefighting aircraft.
Thousands of people - many of them holidaymakers - have been moved to emergency accommodation.
The French authorities have announced that police will stop and search people visiting forests in the south to try to prevent arsonists starting more fires.
"Twenty-nine fires breaking out almost simultaneously in the Var (on Monday), including seven in Frejus... I don't think that there can be any doubt about the theory of criminal intent," Frejus mayor Elie Brun said.
An alleged arsonist appeared in court on Wednesday.
He is accused of causing multiple fires and to have materials in his possession for igniting others this month - but he is not being investigated over this week's fires.
The man under arrest applied unsuccessfully to become a firefighter and was described by the prosecutor in the case as "mentally fragile".
However some officials have said most of the recent fires were probably started by accident or natural combustion in the scorching heat.
Interior Minister Nicolas Sarkozy, who travelled to the region, described the fires as an "ecological massacre".
Four foreign tourists are among the dead. A British teenager and her grandmother were found dead in woods outside the village of La Garde Freinet in the Maures hills.
A Dutch woman and a Polish man also died in the Var region. A man severely injured on Corsica died in hospital.