Police say that the suspects in the attacks in Barcelona and Cambrils were planning one or more bigger attacks than one carried out.
Police are seeking Moussa Oukabir thought to be 17, suspected of carrying out Thursday’s Barcelona attack.
Moussa Oukabir is suspected of using his brother’s documents to rent the van used in the attack.
Hours later, police killed five suspected jihadists in a second vehicle attack in the town of Cambrils. A woman injured in that attack died later.
Mariano Rajoy, Spanish PM condemned what he called a “jihadist attack” in Barcelona. He has announced three days of national mourning and a minute’s silence was held at noon (10:00 GMT) on Friday.