Pictured: The four alleged terrorists being hunted by Spanish police after deadly Barcelona attack

These are the alleged terrorists being hunted by Spanish police after 14 innocent people were killed in twin terror attacks.

The pictures of the smiling, baby-faced boys – two of which are teenagers – have been circulated around the world in a bid to track them down.

They are suspected of being part of a 12-strong terror cell which carried out Europe’s latest atrocity in Barcelona on Thursday.

They have been named in Spanish media as Moussa Oukabir, 17, Mohamed Hychami, 24, Younes Abouyaaqoub, 22, all from Ripoll, and Said Aallaa, 18, from Ribes de Freser.

Moussa, reported to have been the driver of the vehicle in Barcelona, was confirmed dead on Friday evening. He was one of the five attackers shot dead in Cambril by police.

Said Aallaa and Mohamed Hychami were also named locally as among the suspects killed by police.

Some 34 nationalities were among almost 130 people wounded in the attacks in Barcelona's popular Las Ramblas shopping area on Thursday and in Cambrils, a seaside town 70 miles to the south west, early on Friday.

Five terrorists were shot dead in Cambril by a lone police officer as they carried out the second attack, which police have said is linked to Las Ramblas.

Mossos, Catalonia's police force, said on Friday evening that it was continuing to work to identify the driver of the vehicle in Barcelona.

Detectives initially released images of his brother, 28-year-old Driss Oukabir, whose documents are believed to have been used to rent the van that killed 13 people.

However, latest reports suggest Driss handed himself into police on Thursday, saying his younger brother had stolen his ID to hire the vehicle.

Four suspects have now been arrested, but local Catalan police did not reveal the identity of any of them.

Catalan regional police official Josep Lluis Trapero said that a blast at a house in Alcanar, a further 55 miles down the coast, meant the attacks were more "rudimentary" than planned.

Reports from Spain had earlier suggested the terror cell may have been planning an attack using gas canisters.

He said: "We are working on the hypothesis that these attacks were being prepared for a while around this private home in Alcanar.

"We think they were preparing at least one or more attacks in Barcelona.

"The explosion in Alcanar at least avoided some of the material they were counting on to carry out even bigger attacks than the ones that happened.

"Because of that the attack in Barcelona and the one in Cambrils were carried out in a bit more rudimentary way than the one they had initially planned."

He added that one of the five terrorists killed by police during the terror attack in Cambrils may have been the driver of the van which killed 13 people in Barcelona.

Four men are in custody, aged 21, 27, 28 and 34. Three are Moroccan and one Spanish, and police said none of them was previously known to the security services for terror-related reasons.