Police set up a series of roadblocks across northeast Spain on Sunday in hopes of capturing a suspect believed to be connected to the vehicle attacks in Barcelona.
So far, police haven't been able to identify with absolute certainty which member of the 12-person Islamic extremist cell is at large. Police have names for all 12 members of the cell, but three of those members are unaccounted for at this time.
Police, however, said they think the group of extremists were plotting a much deadlier bomb attack.
"Our thesis is that the group had planned one or more attacks with explosives in the city of Barcelona," Catalan police official Josep Lluis Trapero told reporters. That plot was foiled when the house in Alcanar, which was being used as a base, exploded, possibly killing two members of the cell.
Police in Spain are investigating whether a Moroccan imam, who they believe is responsible for radicalizing the cell of young men who carried out the Barcelona attacks on Thursday, died in an explosion linked to the attacks.
An official, speaking on condition of anonymity, said investigators believe Moroccan imam Abdelbaki Es Satty may have been the second victim of a home explosion Wednesday in the town of Alcanar. The president of the mosque where Es Satty preached said he hadn't seen the imam since June, when he announce plans to visit Morocco for three months.
On Saturday, members of the Muslim community denounced the vehicle attacks and offered their sympathy to the families of the victims.
Police told CNN the house in Alcanar was being used as a base to make explosives. A series of controlled explosions were carried out at the site on Saturday.
Police continue searching for the van driver
An international manhunt is still underway for the supposed ringleader of the Islamic extremist cell that carried out the vehicle attacks in Barcelona.
Younes Abouyaaquoub, a 22-year-old Moroccan, is suspected of driving a van into a crowd of people, killing 13 and injuring 120 others.
Despite Abouyaaquoub still being on the run, Spanish Interior Minister Juan Ignacio Zoido declared the terror cell "broken" after five members were killed by police in a shootout on Friday. Four are in custody and one or two others were reportedly killed in Wednesday's house explosion.
As part of the manhunt, Spanish police have searched nine homes in the northeastern town of Ripoll and two buses in northwest Catalonia.
French police have also stepped up security, carrying out extra border checks on everyone coming from Spain.
Spain decided to keep its terrorist threat alert at level 4, declaring Saturday that no new attacks were imminent.
The Associated Press contributed to this report.