Around 800 firefighters, and hundreds of gendarmes and soldiers deployed to battle the flames west of Bordeaux.

More than 20,000 residents and holidaymakers have been forced to flee southwest France due to raging wildfires.

About 800 firefighters were battling the flames some 50 kilometres (30 miles) west of Bordeaux on Thursday, with hundreds of gendarmes and soldiers joining the operation.

Firefighting planes have been dumping water since the blaze erupted on Wednesday. Officials and residents said the fire appeared to have been started by a brush-clearing machine.

The fire began in the village of Saumos, before advancing towards Lege-Cap-Ferret.

Known for its sand dunes, cycle paths and oyster shacks, Lege-Cap-Ferret is popular with French stars.

The blaze advanced quickly through a dense pine forest, ripping through 3,400 hectares (8,500 acres), an area about five times the size of Gibraltar, firefighters said.

Three houses were scorched by the flames and a caravan destroyed, but no casualties have been reported so far.

The European Union deployed three water-bombing aircraft after France sought help, EU officials said.

France has been battered by three heatwaves since May as part of increasingly common extreme weather episodes linked to climate change, causing thousands of deaths, drying up rivers and fuelling wildfires.

“The weather is not on our side,” Lege-Cap-Ferret Mayor Philippe de Gonneville said.  “We have temperatures above 30 degrees Celsius [86 degrees Fahrenheit], with winds that have shifted to the east and northeast and are fairly strong.”

Two firefighters died this week while battling a blaze near Bordeaux airport. Firefighter unions have denounced a lack of resources and said crews were exhausted.

Earlier this month, roaring flames devastated about 10 percent of the UNESCO-listed Fontainebleau forest outside Paris, in a rare such fire so far north.

Fires in 2022 damaged 30,000 hectares (74,000 acres) of forests in France, forcing some 50,000 people to evacuate.

Across Europe, three heatwaves in succession this season have intensified drought, strained water supplies and left vegetation tinder-dry, helping wildfires scorch more land already ⁠this year than the annual average of the past two decades on the world’s fastest-warming continent. The heat has also been blamed for thousands of deaths.