The facade of the apartment building was completely destroyed, and a fire broke out immediately after the explosion, the ABC Espana newspaper reported.
The Spanish police and firefighters managed to enter the building, where they found a man's body in the bathroom, who was believed to be a building resident, the report said.
Eyewitnesses told the newspaper that a gas leak was a possible cause of the incident, adding that they called a fire department because they suspected a gas leak. The explosion occurred the moment a fire brigade arrived, the newspaper reported.
(With UNI inputs)