Driven by strong winds, the fire in the Aude department on the Mediterranean coast, near the Spanish border, had already burnt through 600 hectares (1,500 acres) after breaking out earlier in the afternoon, local officials said.

Some 630 firefighters backed by about a dozen planes were battling the fire, according to the department’s deputy prefect Remi Recio.

Smoke from the fire was causing backups on the A9 coastal highway, AFP reporters said, though the key route to Spain remained open.

Flames destroyed two houses, and local officials converted a local gymnasium into a shelter, although the residents of about 10 evacuated houses were later allowed to return home.

As a precautionary measure, the prefecture later ordered the evacuation of two campsites and a housing estate in the commune of Port-la-Nouvelle on the coast.

Three firefighters were treated for smoke inhalation.

The national weather service had placed the Aude department on orange alert for a “high risk” of fire on Saturday.

The fire comes less than a month after the Aude department was hit by a major blaze that swept through 2,100 hectares near Narbonne, mobilising 1,000 firefighters.