The driver of the van that plowed into crowds in Barcelona, killing 13 people, may still be alive and at large, Spanish police said on Friday, denying earlier media reports that he had been shot dead in a Catalan seaside resort.

Axar.az reports citing Reuters that, Josep Lluis Trapero, police chief in Spain's northeastern region of Catalonia, said he could not confirm the driver was one of five men killed.

"It is still a possibility but, unlike four hours ago, it is losing weight," he told regional TV.

The driver abandoned the van and fled on Thursday after speeding along a section of Las Ramblas, the most famous boulevard in Barcelona, leaving a trail of dead and injured among the crowds of tourists and local residents thronging the street.

It was the latest of a string of attacks across Europe in the past 13 months in which militants have used vehicles as weapons - a crude but deadly tactic that is near-impossible to prevent and has now killed nearly 130 people in France, Germany, Britain, Sweden and Spain.

Suspected jihadists have been behind the previous attacks. Islamic State said the perpetrators of the latest one had been responding to its call to target countries involved in a U.S.-led coalition against the Sunni militant group.

Hours after the van rampage, police shot dead five people in the Catalan resort of Cambrils, 120 km (75 miles) down the coast from Barcelona, after they drove their car at pedestrians and police officers.

The five assailants had an ax and knives in their car and wore fake explosive belts, police said. A single police officer shot four of the men, Trapero said.