120 gas canisters found for 'one or more' attacks in Barcelona: Police

On the eve of the attack in Barcelona, an explosion had occurred at the house about 200 kilometres south of the city.

Police officers stand outside a building during a search in Ripoll, north of Barcelona. | AP

BARCELONA: Police said Sunday they have found more than 120 gas canisters in a house in Alcanar, where suspects of this week's twin assaults in Spain were believed to be building bombs for "one or more" attacks in Barcelona.

"We're starting to see clearly that (the Alcanar house) was the place where they were preparing explosives for one or more attacks in the city of Barcelona," police chief of Catalonia region Josep Lluis Trapero told journalists.

On the eve of the attack in Barcelona, an explosion had occurred at the house about 200 kilometres south of the city, and police believe it was detonated in error by the suspected jihadists.