BARCELONA • Police said the terrorist driver of the van that ploughed into pedestrians in Barcelona may have been killed hours later during a second attack at a nearby beach resort.

Earlier, they had said they were looking for Moussa Oukabir, the 18-year-old brother of one of the suspects arrested following deadly attacks in Spain's Catalonia.

"We are looking for Moussa Oukabir, but for the moment, we don't know whether he was the driver of the van," police said.

On Thursday, Moussa's brother, Driss Oukabir, 28, was arrested in Ripoll, about 100km north of Barcelona, just hours after the van attack. Initially named as a suspect, he later gave himself up at a police station there.

Three others were also reported to have been arrested in connection with the attacks.

Five attackers that struck yesterday in Cambrils, 120km south of Barcelona - where an Audi A3 car rammed into pedestrians - were killed in a gunfight with police. They had been wearing fake suicide belts.

Police suggested that Moussa may have later joined the four other extremists shot dead in Cambrils.

Moussa, said to be a Spanish national of Moroccan descent, was believed to have stolen his older brother's identity documents to rent the white Renault van used in the Barcelona attack, the Daily Mail reported. The paper said Moussa had written about "killing infidels" in what it called a chilling online post.

In photos in the Daily Mail taken from Moussa's social media accounts, the teenager is seen smiling and posing. He also posted pictures of his dog, a Staffordshire bull terrier called "Vinny" online, the paper said.

The Daily Maily said Moussa posted on the Kiwi social network that, if he was king of the world, his first act would be to "kill the infidels". Asked where he could never live, he replied: "The Vatican", the paper said.

The paper added that Moussa also rated girls' profile pictures on the website, and joked that he would shoot someone who lied to him.

• Additional information from Agence France-Presse