A gas explosion ripped through an apartment building in north-eastern Spain on Wednesday, injuring at least 25 people, authorities said.
The blast occurred about 3am (1300 AEDT) in Gava, a town just south-west of the Catalan capital, Barcelona.
At least 17 people were seriously injured, including two children, the Catalonia regional government said in a statement.
Television footage showed gaping holes in the front, sides and roof of the three-story building. Curtains and blankets draped from ruined apartments, while pieces of furniture and electrical appliances blown from the building littered the area outside.
As dawn broke, firefighters were still searching for more possible victims and working to put out flames that could be seen shooting across the building's roof.
"We heard a loud explosion and we ran out. The building was completely destroyed," Juan Exposito, who lives opposite the damaged building, told the digital edition of the Barcelona newspaper La Vanguardia.
Authorities said the building had four apartments on each floor. It was unclear how many people were in the building at the time of the blast.
Some 50 people evacuated from nearby buildings gathered on the pavement to watch the incident. They were allowed to return to their homes by midmorning.
The regional government said it was not immediately known what caused the gas to explode. It said the building's four walls and structure were seriously damaged. The statement said 23 firefighting units had been sent to the scene.
Gava is an industrial and farming town with a population of some 50,000.