In some places, locals used spades, rakes and even tree branches in a desperate bid to beat back the flames until the firefighters arrived.
Emergency workers, who have been fighting the blazes for three days now, were also battling infernos in the mountainous hinterland, and on the island of Corsica.
Thousands of tourists fled to the safety of public shelters after a fire broke out overnight in the village of Bormes-les-Mimosas, on the Cote d’Azur, and swept towards the area’s campsites.
“We were slapping it with branches to prevent it from spreading, but it came back here,” said Bastien Guyomard, a resident of Toulon who is visiting Bormes-les-Mimosas.
“We contained it until the firemen came, an hour and a half later or even two hours, but… the firemen are spread out everywhere. There’s fire everywhere.”
The head of the rescue operation in Bormes-les-Mimosas, Serge La Vialle, told AFP that more than 550 firefighters backed by five water bomber aircraft had not yet managed to contain the flames.
“It’s moving slowly and even growing a bit,” he said.
Some of the evacuees ended up spending the night on the beach, but many families took shelter in a local gymnasium and public hall where volunteers served up drinks and breakfast.
Amelie, a German tourist from a family of nine, said she had woken to the sound of sirens. “We all gathered on the beach. The mountain was ablaze and the sky was red,” she told AFP.
“The hills were all on fire, running right down to the sea,” Jean-Paul Poinsart, 68, said.
Since Monday, firefighters have been criss-crossing the southeast trying to extinguish infernos in a tinder-dry region buffeted by strong winds.
About 100 kilometres northwest of Bormes-les-Mimosas, a pine forest in Peynier caught fire on Wednesday.
Local authorities said it risked consuming 1,000 hectares of forest but that no homes were in danger.
Prime Minister Edouard Philippe was due to visit the area on Wednesday evening.
In a tweet Wednesday, President Emmanuel Macron expressed his admiration and support “for those fighting relentlessly against the fires ravaging our territories.”
He also expressed his support for those forced to flee their homes.
In all, over 6,000 firefighters, troops and civil security officials backed by 19 water bombers have been deployed.
At least 12 firefighters have been injured and 15 police officers affected by smoke inhalation so far, officials said.
On Tuesday, Italy answered a French request for help, sending an extra two planes to scoop water from the sea to douse the flames.
‘Work of arsonists’
France’s Cote d’Azur bulges in July and August as holidaymakers head to the beach.
Bormes-les-Mimosas “doubles or triples its population in summer”, a local fire official said.
The area is experiencing a particularly hot and dry summer that has made it especially vulnerable to fires.
Officials said they suspected Tuesday night’s blaze, which started in a caravan storage yard, was the work of arsonists. Other fires have been blamed on discarded cigarettes.
The fires have devoured around 7,000 hectares (27 square miles) of forest across southeast France and Corsica.
On Tuesday, a fire ripped along the coast in La Croix-Valmer near Saint-Tropez, a resort frequented by the rich and famous.
La Croix-Valmer’s deputy mayor Rene Carandante described a landscape of blackened headlands fringed by charred umbrella pines, where green forest had once framed the azure waters of the Mediterranean.
“It’s a disaster area. There’s nothing left,” he said.
Northeast Corsica was also counting the ecological cost of fires.
Aerial footage of the region Wednesday showed vast tracts of forest blackened and bare.
Experts say said a drop-off in farming in southeast France since the 1970s has allowed forests to mushroom, making the region more prone to fires.
A proliferation in the numbers of homes, roads and power lines has also increased the fire hazard.
Portugal, meanwhile, which last month suffered deadly forest fires, has been battling fresh blazes since Sunday in centre of the country, forcing the evacuation of around 10 villages.
About 1,100 firefighters have been drafted to stop the advance of the flames in the same area that was engulfed by fire last month, leaving 64 people dead.