The CIA warned local Barcelona police two months ago that the city's famous Las Ramblas tourist strip could be targeted in a terrorist attack like what occurred today, it has been reported, Mirror reported.
The warning came after a wave of van or lorry-style attacks targeting pedestrians on streets around Europe including London Bridge, Finsbury Park and Westminster Bridge in the UK as well as Nice, Berlin and Stockholm.
Local Spanish newspaper El Periodico reports of the warning following shocking scenes in Barcelona this afternoon after a terror attack.
"The CIA warned the Mossos (local police) two months ago that Barcelona, and in particular the Rambla, could be the scene of a terrorist attack like the one that occurred this afternoon," the newspaper reported.
At least 13 people are feared dead and 119 people are believed to have been injured in the attack in central Barcelona.
In May, the United States issued a new terror alert for Europe this summer.
The state department cited the Westminster atrocity as evidence of Islamic State's ability "to plan and execute terrorist attacks in Europe".
It was concerned "terrorist sympathisers or self-radicalised extremists" could carry out attacks at any time, with no warning.
The potential for large vehicles to inflict mass casualties was laid bare in horrifying fashion in July last year when a lorry drove through crowds gathered to celebrate Bastille Day in Nice, killing 86 people and injuring scores more.