According to the Catalan police chief, Thursday's attack hasn't been "committed on the full scale" because explosives had been destroyed as a result of an accidental blast in Alcanar a day before the terror attacks.
"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," Josep Lluis Trapero, chief of Catalonia’s police force (Mossos d'Esquadra) said.
Catalan police also said that the ramming attack in Barcelona was conducted by one person. Police still don't know if the attack perpetrator is still at large. He may have crossed the Spanish border with France. The police added that the increased measures of control were still in place in Catalonia, especially on the border with France.
"We think that one person committed this crime," Trapero said at a press conference, broadcast on the El Pais newspaper's website.
Speaking about 22-year-old Moroccan national Younes Abouyaaqoub, who is believed to be the perpetrator of the Barcelona van attack, Trapero said the police could not confirm whether he was the driver. "We cannot confirm so far who was the driver of the van in Barcelona" Trapero said.
The official confirmed that four terrorists out of 12 suspects in the attack have been arrested and five others were killed. The identities of three suspects were established. Two or three more attackers allegedly died in an explosion in the Catalan town of Alcanar a day before the ramming attack, while one suspect remains at large.
The official added that one of the suspects could have visited a Western European country.
On Thursday, a van plowed into a crowd of pedestrians on Las Ramblas street in Barcelona, killing 13 people and injuring more than 130 others, in what police said was an act of terrorism.
Hours after the incident, another vehicle attack took place in the coastal town of Cambrils, south of Barcelona, killing one and injuring five civilians as well as a police officer. Daesh terrorist group claimed responsibility for the attacks.
On Saturday, the Spanish Interior Ministry said that a terror cell has probably been behind the Barcelona attack.
The terrorist cell prepared explosives in a house in Alcanar town 120 miles south of Barcelona, using gas canisters and explosive material known as the "Mother of Satan," according to the local media reports. But the gas cylinders accidentally detonated, destroying the house and killing two-three people the night before the attacks in Barcelona and Cambrils, which made the perpetrators change their plan for the attack. The media also pointed out that the terrorists initially saw the Sagrada Familia cathedral in Barcelona as their only target.