Planes and helicopters are fighting the flames from the air
Firefighters are trying to contain the last of the major forest fires which have devastated parts of southern France in recent days, killing five people.
But several fresh blazes broke out on Wednesday, including one at Salon-de-Provence, where 17 firefighters were hurt, two seriously.
Dry weather and soaring temperatures have led to hundreds of blazes throughout Europe.
More than 500 firefighters and 300 soldiers have been fighting forest fires in central Portugal, one of which killed an elderly man as it swept through his home.
Temperatures of 40C have hindered the operation, and the flames have charred large areas north-east of the capital, Lisbon.
In France, helicopters were dropping hundreds of gallons of water on a fire at La Motte, near the Cote d'Azur, as around 700 firefighters worked on the ground.
Foreign firefighters - from Italy and Russia - have been helping their French colleagues while Greece and Norway have offered to send firefighting aircraft.
Officials said the forests were being doused to prevent the further spread of the fires if the fierce local winds, known as the "mistral", strengthen again.
Thousands of people - many of them holidaymakers - have been moved to emergency accommodation since around two dozen fires broke out on Monday.
The French authorities announced earlier that police would 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 told the French news agency AFP.
But other officials said most of the fires were probably started by accident or natural combustion in the scorching heat.
"The myth of the evil arsonist must not become a permanent alibi
that lets everyone else off the hook," said Bernard Foucault,
in charge of forest protection on the Mediterranean coast.
"The person who most often starts a fire is Mr or Mrs Everyman."
The authorities are promising severe punishment for anyone who does deliberately start fires.
A man accused of starting several fires appeared in court on Wednesday afternoon.
He is alleged to have caused 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".
Interior Minister Nicolas Sarkozy, who travelled to the region, described the fires as an "ecological massacre".
Four foreign tourists are among the dead in France. 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.