Spanish firefighters supported by two dozen water-dropping aircraft have been working in temperatures of around 40C to try to control a forest blaze that forced the evacuation of around 1,000 people.

Authorities said more than 300 firefighters with 65 vehicles were deployed to the wildfire near Valencia, around 220 miles south-east of Madrid.

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The head of the Emergency Response and Security Agency, Jose Maria Angel, told reporters the aircraft were dumping water every four minutes.

Temperatures in the area were forecast to remain high, but officials were hoping a stiff wind that has fanned the flames would diminish.

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Emergency services said they almost brought the blaze under control on Sunday, but when the firefighting aircraft stood down after sunset the fire surged again and compelled the evacuations.

Authorities say they suspect the fire was started deliberately.