Police have stepped up their search for Younes Abouyaaqoub as the main focus of the investigation into the van attack that killed 13.
Three suspects who were also wanted are now believed to have been shot dead in the later attack in Cambrils.
The man thought to have rented the van that ploughed into pedestrians in Barcelona is believed to be dead, say Spanish civil guard sources.
But this has not been officially confirmed by local police who warn the suspect may still be at large.
Moussa Oukabir, who is thought to be 17 or 18 years old, is said to have been among the five suspected terrorists killed following the attack, according to a union official for Spain's Civil Guard
Oukabir was suspected of using his brother's documents to rent the van which ploughed through pedestrians in the popular Las Ramblas shopping area.
Mossos, Catalonia's police force, said it had identified those shot by police but did not confirm their names.
