BARCELONA - Spanish police on Monday shot down a man who local media identified as the Islamist militant who drove a van into a Barcelona crowd last week, killing 13 people.

Police did not immediately give the man's identity, saying only that he had appeared to be wearing an explosive belt in the "incident" in Subirats, a town near Barcelona. They said only that a bomb squad was using a robot to approach the man's body.

Some Spanish media, citing investigative sources, said police had shot dead 22-year-old Younes Abouyaaqoub, on the run since Thursday when he drove at high speed into heavy crowds strolling along Barcelona's most famous avenue, Las Ramblas.

It was Spain's worst militant attack in over a decade, with Islamic State claiming responsibility.

"The suspect wore what appeared to be an explosive belt. He has been shot down," police said in an official tweet that did not make it unequivocally clear that he had been killed.

Local media said the man was spotted by a woman in the early afternoon and then fled through vineyards but police managed to find and shoot him on a road near a sewage treatment plant.

Police had asked the rest of Europe to join the manhunt for the Moroccan-born man. They say he fled Las Ramblas on foot amid the chaos of the attack then hijacked a car, stabbing the driver to death, before crashing through a police checkpoint.

Abouyaaqoub had been the only one of 12 accomplices still at large. His mother, Hannou Ghanimi, had appealed for him to surrender, saying she would rather see him in prison than end up dead.

Four people have been arrested so far in connection with the attacks: three Moroccans and a citizen of Spain's North African enclave of Melilla. They will be taken to the high court in Madrid, which has jurisdiction over terrorism matters.

Abouyaaqoub lived in Ripoll, a town north of Barcelona close to French border.

Islamic State claimed responsibility for the Barcelona attack as well as a separate deadly assault hours later in the coastal resort town of Cambrils, south of Barcelona.

In Cambrils, a car crashed into passersby and its occupants got out and tried to stab people. Five suspects were shot dead by police, while a Spanish woman died in the attack.

In the roughly seven hours of violence that followed the van's entry into the pedestrian boulevard of Las Ramblas on Thursday afternoon, attackers killed 15 people: 13 on Las Ramblas, the Cambrils victim and the man in the hijacked car.

Of the 120 injured on Las Ramblas, nine remain in a critical condition in hospital.