Police in Catalonia hunting the Barcelona terror attack suspect have shot dead a man who appeared to be wearing an explosive belt.

Police confirmed that an operation was under way in Subirats, to the west of the city.

Spanish media reported that Younes Abouyaaqoub, the 22-year-old Moroccan named as the chief suspect, was detained during the operation on Monday afternoon.

A banner reading in Spanish A banner reading in Spanish “We are not afraid” is seen next to flags, flowers, messages and candles for the victims of the Barcelona attacks (Emilio Morenatti/AP)

One radio station reported that a man wearing a suicide belt had been shot by police.

Thirteen people were killed in the attack in Las Ramblas in Barcelona on Thursday night, including seven-year-old British boy Julian Cadman.

Joaquim Forn, head of home affairs in Catalonia’s regional government, said earlier on Monday that “everything indicates” Abouyaaqoub was behind the wheel.

Abouyaaqoub, who fled on foot, was believed to be the only at-large member of the 12-strong terror cell behind the attacks in Barcelona and the seaside town of Cambrils.

The death toll from the two attacks rose to 15 on Monday when a second victim of the Cambrils attack died in hospital.