Barcelona attack: Police probes role of 'missing' radical Islamic leader

Abdelbaki Es Satty is suspected to have radicalised several young people at Ripoll

Grief-stricken Barcelona paid homage on Sunday to victims of two terror assaults at a mass in the city's Sagrada Familia church, as investigators turned their focus to a missing Moroccan imam, who is believed to have radicalised the young attackers.

King Felipe, Prime Minister Mariano Rajoy and Catalonia's president Carles Puigdemont led the ceremony mourning the 14 people killed by jihadists who used vehicles to mow down pedestrians in Barcelona's Las Ramblas boulevard on Thursday and in the nearby seaside resort of Cambrils early Friday.

"These have been days of tears, many tears," said auxiliary bishop Sebastia Taltavull.

Outside the church, snipers were posted on rooftops surrounding the landmark building by Gaudi, while heavily armed police stood guard as hundreds of people gathered under grey skies.

Catalonia resident Teresa Rodriguez said she had turned up to pray for the victims.

"What happened in Las Ramblas is really hard for us, we go for walks there often, it could have happened to me, my children or anyone. And here we are. It's huge, huge," she said as she fought back tears.

Later on Sunday, nearly 100,000 people were expected at Barcelona's Camp Nou stadium for their team's first game of the season, to be marked by a minute of silence for the victims.

Interior Minister Juan Ignacio Zoido said on Saturday that the cell behind the carnage that also injured 120 had been "dismantled," although local authorities took a more cautious tone.

Police were still hunting 22-year-old Younes Abouyaaqoub, who media reports say was the driver of a van that smashed into crowds on the popular Las Ramblas boulevard on Thursday, killing 13 people.

Hours later, there was a similar assault in the seaside town of Cambrils that left one woman dead. Police shot and killed the five attackers, some of whom were wearing fake explosive belts.

An extensive security operation including roadblocks was mounted overnight across Catalonia.

The Islamic State (IS) group claimed responsibility for the attacks, believed to be its first in Spain.

The terror cell in Spain reportedly comprised at least 12 young men, some of them teenagers.

Investigators are seeking to unravel the role of an imam, Abdelbaki Es Satty, who is believed to have radicalised many of the youths from a small town called Ripoll, at the foot of the Pyrenees.

Several of the suspects - including Abouyaaqoub - grew up or lived in the town of about 10,000 inhabitants.

On Saturday, police raided the imam's apartment in Ripoll, his flatmate, who would only identify himself as Nourddem, told AFP.

Spanish media quoting police sources, said the officers were looking for DNA traces in the apartment to compare with body parts found in an explosion in a home in Alcanar, about 200 kilometres (120 miles) south of Barcelona, where the alleged jihadists were believed to have been building bombs.