Warning - graphic content. A video from the scene of the Barcelona attack shows the horrific aftermath.
Catalan investigators raided the house of an imam in the town of Ripoll they believe may have overseen the cell which killed 14 people in twin terrorist attacks in Barcelona and the seaside resort of Cambrils.
Spanish police are trying to piece together how a cell composed of multiple sets of brothers from the same sleepy Pyrenees town came to carry out the devastating attacks, amid reports they planned to blow up the Sagrada Familia.
The home of imam Abdelbaki Es Satty was raided with officers reportedly seeking - among other evidence - DNA samples which might link him to a building in the town of Alcanar believed to be where the attack was prepared.
El Pais reported they were investigating whether the imam, who apparently left Ripoll around a month ago, might be one of two dead bodies discovered in the Alcanar house. Sources involved in the investigation told El Confidencial they believed he was a "spiritual or ideological leader" to the cell members, radicalising them and helping them to plan the attacks.
The sources cited the lack of previous terror links among the group, and said they had detected a number of trips by some members to France and Morocco. Police did not officially confirm or deny the reports.
Many questions remained as Spanish authorities continued a manhunt for a 22-year-old missing member of the cell.
Unlike other vehicle attacks Europe has endured in the last two years - in Nice, Berlin, Stockholm and London - Friday's in Barcelona displayed an unusual degree of sophistication and coordination. Authorities are investigating what they believe to be a terrorist cell of at least 12 members.
Personal belongings lie on top of a bed after a police raid on the house of the Oukabir family where Driss Oukabir and Moussa Oukabir, two possible suspects lived in Ripoll, Spain. Photo / AP
But the Spanish Government was quick to insist that the situation was under control. Interior Minister Juan Ignacio Zoido lvarez said that the cell had been "dismantled," and the Government ultimately declined to raise the national alert level from four to five, the highest-possible classification.
Inspector Albert Oliva, chief spokesman for the national Catalan police, said the local police force spearheading the investigation cast doubt on the Government's proclamation. "We must remember who is the leader of the investigation," he said, highlighting the work that remains to be done. Oliva then said that raids had failed to produce the missing suspect. When asked about the potential for another attack still to come, he said the prospect was unlikely but could not be deemed impossible.
Many loose ends still remain. For one, there is the rare social uniformity of the suspects' backgrounds: most of the 12 people identified as members of the cell come from the same small town near the French border, almost all are of Moroccan immigrant origins and all are under the age of 35.
Then there are the puzzling logistics. The suspects ultimately struck three different locations in quick succession - one by accident. Propane and butane canisters that police believe the suspects intended to detonate in Barcelona exploded prematurely in Alcantar.
Investigators at the site, where controlled explosions were carried out, later discovered a stockpile of explosive material including more than 100 gas canisters. Local media reported that a crude and unstable homemade explosive known as acetone peroxide was being produced in the house.
The Sagrada Familia. Photo / AP
Neighbours speculated that recent high temperatures in the heatwave known as Lucifer might have triggered the explosion.
That may have saved Barcelona from an even more devastating attack. Catalan police said they believed the group had been preparing to use the explosives, either against one target or in multiple coordinated attacks.
They could not confirm or deny reports in two Spanish newspapers that the cell's "Plan A" was to blow up the Sagrada Familia, the iconic Barcelona cathedral designed by Antonio Gaudi.
On Friday, the driver who struck Barcelona's most famous promenade was somehow able to escape from the scene on foot. The same suspect may then have been among the group of five that committed a second vehicle attack just hours later in Cambrils, police believe.
The missing suspect is Younes Abouyaaqoub, according to Catalan police officials cited in Spanish media. Police believe he left Las Ramblas after the rampage, hijacked a car after killing the driver, and drove out of the city. Police found a dead body with multiple stab wounds in an abandoned vehicle outside the city.
For answers, all eyes have turned to Ripoll. The head of the Ripoll mosque at which Abdelbaki Es Satty preached said he had arrived just over a year ago and left at the end of June, when he asked for three months' holiday to visit Morocco and was denied.
