The fire, the latest of several in the area in recent days, started on the property of a winery south of the city of Narbonne on Monday afternoon, then spread rapidly due to wind and parched vegetation after a heatwave.

More than 1,000 firefighters battled the flames overnight, but by the morning the inferno had partially damaged 2,000 hectares (4,900 acres) of land and was still going strong, local authorities said.

Local official Christian Pouget said six homes had been partially affected.

"The fire has still not been brought under control," he said.

In the village of Prat-de-Cest on Tuesday morning, trees were blackened or still on fire.

As she watched fire trucks drive to and fro, retiree Martine Bou, who did not give her age, recounted fleeing her home with her cats, tortoises and dog on Monday afternoon before returning.

But her husband Frederic stayed all night to hose down the great pines on the other side of the road so the fire would not engulf their home.

"I've never seen anything like it. I have never lived next to such an enormous fire," he told AFP, reporting flames dozens of metres (more than a hundred feet) high.

French weather service Meteo France said the risk of fires remained high on Tuesday.

Authorities closed the A9 autoroute to Spain, but on Tuesday morning they said they were progressively reopening the route to traffic.

Meteo France said this weekend that a punishing heatwave that began on June 19 had officially ended on Friday, lasting in all 16 days -- the same length as the country's deadly 2003 heatwave.

That same day, however, the first major fires of the season broke out in the south.

Scientists say human-induced climate change is increasing the intensity, length and frequency of the extreme heat that causes some forest fires.