“The are very strong gusts of wind generating a speed and progress that make efforts to extinguish it difficult,” a commander of the military emergency unit, David Barona, told state TV channel 24H.

“The smoke plume is spreading at a low altitude making it difficult for air assets to access the area.”

Up to 250 firefighters are fighting the blaze in an area called Pinofranqueado, in Caceres province, near the border with Portugal.

Authorities have ordered the evacuation of as many as 550 people in the villages of Cadalso, Descargamaría and Robledillo de Gata.

Natural causes sparked the fire, according to authorities.

“It’s a very large attack on vegetation and the area,” the head of Extremadura emergency services Nieves Villar told reporters.

An unusually dry winter across parts of southern Europe coming after three years of below-average rainfall in Spain have raised the risk of wildfires.

Some 493 fires destroyed a record 758,000 acres in Spain last year, according to the European Forest Fire Information System.