Catalan Police say up to three terror suspects could be on the run, as they can not identify the remains of bodies recovered in an explosion at a house, south of Barcelona.
The villa in Alcanar is believed to have been a bomb factory, where last week's twin attacks in Spain were being planned.
Officers initially thought it was an accidental gas explosion.
A woman living opposite the house has said she knew it was not just a gas explosion when she heard the noise.
"We weren't really sure what it was but something really big had just happened and I doubt this was only a gas explosion because to me, it smelled like a bomb," she said.