Four people were killed on Tuesday, one of them a child, in a gas explosion in a home in the Alicante town of Villajoyosa.
Investigators are trying to work out if the explosion was caused by gas canister, or if the origin was a fire in the surrounding shrub land.
Meanwhile, the president of the government of Spain, Mariano Rajoy, issued a personal statement of condolence to the family and friends of the victims.