(CNN) Firefighters in Spain are battling a major wildfire that probably started after a heap of manure self-ignited amid the intense European heat wave.

Around 10,000 acres of forest and other vegetation were affected by the blaze near Tarragona in the country's north-east, according to the Catalan regional government.

Trees burn during the forest fire west of Tarragona on June 27.

Authorities said the fire likely began when an "improperly managed" pile of manure self-combusted in the heat , causing sparks.

Spontaneous ignitions can occur when flammable materials, such as piles of hay, compost or manure heat up to a temperature high enough to cause combustion, according to the US National Park Service.

Residents gather to observe a forest fire raging near Maials in the northeastern region of Catalonia on June 27, 2019.

As of early afternoon, the fire was still not under control and 53 people have been evacuated from the area.

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