Catalan government official Joaquim Forn also told local radio earlier on Friday that it was possible that attackers had meant to use canisters in the attack on Thursday in which a suspect drove a van at speed along a busy pedestrian street.
Security forces are hunting for the van's driver, who was seen escaping on foot, and police said they had killed five attackers on Friday night in Cambrils, a town south of Barcelona, to thwart a separate attack.
"The priority right now is work out the identity of these people, to prove and show the relationship between the different people involved, those that took the van and those that have been able to escape," Forn said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
Follow NDTV for latest election news and live coverage of assembly elections 2019 in Maharashtra and Haryana.
Subscribe to our YouTube channel, like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.