Spain's prime minister has said the attack on Barcelona was "jihad terrorism".
Mariano Rajoy said his country is mourning in solidarity with Barcelona and other European cities hit by deadly extremist attacks.
Rajoy traveled to Barcelona following the van attack that killed 13 people and injured 100.
He said the victims and their family and friends "are in this moment our main priority".
Three days of mourning have been declared to honour the victims of the attack.
Two men charged with murder and membership of a terror organisation as judge orders a fourth suspect to be freed on bail.
Younes Abouyaaqoub was wearing a fake bomb vest when he was killed in the town of Subirats, about 30 miles west of Barcelona.
The man believed to be responsible for driving a van into pedestrians in Barcelona has been pictured as the death toll rises to 15.