BARCELONA, Spain -- Spanish police hunting for the man who they consider to be the final member of a cell that carried out vehicle attacks in Barcelona and a nearby town that left 15 people dead and more than 120 others injured shot and killed a man west of the Spanish city on Monday.

Police were searching throughout the northeastern region bordering France for Younes Abouyaaqoub, whom Catalan authorities believe drove a van down the popular pedestrian promenade in Barcelona known as Las Ramblas on Thursday last week.

Catalonia's regional police force confirmed an operation in Subirats, a town about 15 miles west of Barcelona, later Monday, and said later that a "suspicious person," wearing something that looked like an explosive belt, had been fatally shot. The police did not confirm the person shot was Abouyaaqoub, and reporters on the scene said it was impossible to identify the man immediately as he was laying on the ground, face down.

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Police bomb squad officers were using a robot to approach the slain man.

At least two Spanish news outlets, citing anonymous sources, said the slain man was the Barcelona attacker.

Abouyaaquoub, a 22-year-old Moroccan, is suspected of killing 14 people and injuring 120 in that attack alone.

Another attack hours later killed one person and injured others in Cambrils, a seaside town south of the city. Police say the cell consisted of 12 men, all with connections to the northern town of Ripoll.

Catalan interior minister Joaquim Forn told Catalunya Radio on Monday that "everything indicates" that Abouyaaqoub, a resident of Ripoll, was the van driver.

Forn also said Abouyaaqoub was thought to be the sole remaining member of the 12-man cell still at large. His brother and two cousins have been killed.

If you have any information about terrorist attack on #Barcelona #Cambrils mossos.terrorisme@gencat.cat or 📞937285220 pic.twitter.com/nFFaJPhHR3 — Mossos (@mossos) August 21, 2017

Forn told the radio station that his country's law enforcement agencies had notified European police colleagues of Abouyaaqoub's identity, and the hunt for him, "because this person... is likely being sought in all European countries."

Police in Catalonia, the northeastern province of Spain where the attacks occurred and where the terror cell was based, released photos of the suspected driver via Twitter on Monday without naming him, warning civilians that he could be armed.

Catalonia police chief confirmed reports on Monday that the driver of the van made his getaway on foot after plowing through scores of people on Las Ramblas.

Images released on Monday show a slim man wearing sunglasses seemingly walking through what newspaper El Pais said was the traditional La Boqueria market, just off Las Ramblas, after the attack.

The police said the suspect hijacked a vehicle after escaping on foot, and that a person was found dead of knife wounds inside that vehicle. The victim was confirmed as the 15th fatality in the attack on Monday.

Investigators believe the terror cell was based in the town of Ripoll, and that its members may have been radicalized at least in part by the former imam at the local mosque, Abdelbaki Es Satty. Es Satty was one of two people killed in an explosion in Ripoll, home to most of the cell members, in the days prior to the Barcelona attack. Gas canisters -- suspected components of a large improvised explosive device the cell was working on -- blew up in a home in Ripoll.

It appears the cell decided to carry out the low-tech vehicle attack in Barcelona after the explosion, fearing it would alert Spanish law enforcement to their plotting.

A Catalan official said earlier that regional and local authorities had discarded the Spanish government's suggestion to place traffic barriers to protect Las Ramblas because they deemed them "inefficient."

Catalan regional president Carles Puigdemont told La Sexta television that regional and municipal authorities discarded the suggestion because the barriers wouldn't have prevented vehicles from entering the promenade at other points. Besides that, Puigdemont said closing off Las Ramblas was impractical because emergency vehicles still would need to be able to access the area.

Reports said the suggestion was made after other big vehicle attacks in Europe, but the precise timing wasn't clear.

Meanwhile, in Sydney, Australia, a school was mourning the loss of a 7-year-old student who was killed when the van careened down Las Ramblas.

Julian Cadman, a dual citizen of Australia and Britain, was enjoying the sights of Barcelona with his mother when a van sped down the promenade. His mother was injured in the attack and was hospitalized.

Greg Whitby, executive director of the Catholic Education Diocese of Parramatta, said in a statement Monday that Cadman had been a beloved second grade student at St. Bernadette's Catholic Primary school in Lalor Park, a western Sydney suburb.

Whitby said Cadman was "a delightful little boy -- curious and energetic with a kind and generous heart." He said Cadman was much loved and the school community was feeling his loss deeply.