Spanish officials have named the man suspected of driving a van into Las Ramblas last week.
Joaquim Forn – the head of home affairs in the regional government of Catalonia – told a local radio station all of the indicators point towards Younes Abouyaaqoub.
The 22-year-old Moroccan is thought to have fled into France on foot as the authorities continue to pursue him.
Officials believe he was the man behind the wheel of the van which killed 13 after it was driven into crowds of people on Las Ramblas, Barcelona's central tourist hub.
Abouyaaqoub is reported the only surviving member of a terror cell of 12 which planned the attacks in Barcelona and the nearby town of Cambrils.
The whereabouts of three of the group are currently unknown, but it’s thought two of them died in an explosion at a house in Alcanar last Wednesday.
CCTV footage purportedly showing Abouyaaqoub has been released by Spanish newspaper El Pais.