An out-of-control wildfire is raging in Spain's southern region of Andalusia, forcing more than 3,100 people to evacuate, authorities said Sunday.

The blaze broke out Thursday in the mountains near the town of Almonaster la Real, 120 kilometers (75 miles) northwest of the city of Seville. It has already scorched 100 square kilometers (38.5 square miles).

Sixteen helicopters and eight planes are helping more than 500 workers tackle the blaze, including firefighters and army emergency personnel who worked around the clock this weekend.

"It is very difficult to say when the wildfire will be under control," said Juan Sanchez of the Andalusia Forest Fire Department, as weather conditions are playing a key role.

The wind dropped overnight, making their task a little easier, but authorities expect the fire will be fueled by strong winds later Sunday. Crews were also struggling to reach all affected areas because of the rugged terrain, officials said.

A further 70 people were evacuated Saturday because of a wildfire in Mula, a small town in Spain's southeastern region of Murcia, while firefighters are also trying to extinguish two wildfires in the western region of Extremadura.