The Spanish Police have intensified their search for the driver of a van that plowed through pedestrians in the tourist district of Las Ramblas in Barcelona, Spain.

On Thursday, a Fiat van drove into crowds in the historic city with the intention of killing as many people as possible in what the police suspect to be one of multiple planned terrorist attacks.

A senior police officer said the van attack was linked to an explosion that took place in Alcanar, about 100 kilometers south of Barcelona on Thursday morning in which one person was reportedly killed.

Ethan Spibey who witnessed the attack said: “All of a sudden, it a was real kind of chaos. People just started running and screaming. There was a kind of mini stampede. It seems like a lot of people have taken refuge in shops and local cafes”.

Mid-August is the height of the tourist season in Barcelona which has been described as the top destination for most tourists in Europe.

The Spanish police have already apprehended four people in connection with the attack. The search for the main culprit who, according to the Spanish Interior Ministry, killed 13 people, left 15 with serious injuries and another 65, all of different nationalities, with less serious injuries has been intensified.