They entered at the northern edge of the street and careened more than 600 yards through the pedestrian section, according to Rac1, zig-zagging through the crowds.
"Messi is a victor, he is the best player in the world".
Barca star Messi was among the first players to respond, writing via his official Instagram page: "I want to send my condolences and all my support to the families and friends of the victims of the bad attack in our beloved Barcelona. There are many more of us who want to live in a world of peace, without hate and where respect and tolerance are the bases of living together".
Barcelona condemned the attack and expressed its "profound sorry and utter disgust" at Thursday's atrocity.
"FC Barcelona and Leo Messi have agreed on a contract renewal that will keep the Argentinian at the club until June 30th, 2021", a statement from the club confirmed.
Messi is thought to be unhappy with Barcelona's board at the minute, and has several concerns over the direction of the club, and following the loss to Real Madrid in the first leg of the SuperCopa, even took to social media to express that.
Earlier this month, Messi saw his close pal Neymar leave Barcelona to join Paris Saint-Germain in a €222m (£201m, $260m) world record transfer.
Barcelona's cross-city rivals, Espanyol, also released a statement offering their support to those affected by the attack. "All the support and solidarity (to ) the family and friends of the victims".