A tourist in Barcelona has told ITV News she saw a "white van not slowing down" drive past her as people ran during the attack.
The American tourist added that police followed the van telling everyone to "get inside as soon as possible".
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.