A forest fire in southern Spain has forced the evacuation of 1,000 people and is threatening a national park famous for its biodiversity, authorities said Sunday.

The flames have advanced westward and have entered Donana National Park, one of Spain's most important nature reserves and home to the highly endangered Iberian lynx.

"The fire has entered in the limits of the reserve, and that is where we are focusing our efforts," Jose Gregorio Fiscal Lopez from the regional Andalusian authority in charge of the environment, told Spanish national television.

Susana Diaz, the regional president of Andalusia, said "there is no risk to the population" after a 1,000 people were evacuated from campsites and houses near the town of Moguer on Spain's southern coast where the fire started on Saturday night.

The blaze is being treated as a level 1 - or maximum threat - by emergency services.

By 11 a.m. (0900 GMT) on Sunday emergency services had deployed 11 planes, 10 helicopters and dozens of land vehicles against the flames in a joint military-civilian operation.

Televised images showed trees engulfed by flames during the night.

Diaz said the fire was proving difficult to fight due to the hot weather and shifting winds.

Like much of Spain, the area near Huelva is on high alert for forest fires because of a heat wave. Last week, 63 people died in a forest fire in neighboring Portugal.