A majority of the suspects in the Barcelona attacks are young men from the small town of Ripoll, in northern Spain. Many members of the town are in shock about these attacks and are also speaking out in support of the Muslim community. (Raul Gallego Abellan/The Washington Post)

Desperate to ease public fears and neutralize a terrorist cell responsible for the deadliest attack in Spain in a decade, Spanish police erected 800 checkpoints across the region of Catalonia on Sunday — part of a massive manhunt for a Moroccan-born man they suspect was the driver of the van that killed 14 and injured scores in Barcelona last week.

Authorities could not say whether Younes Abouyaaqoub, 22, was still in Spain or had crossed the border into France, but they were clearly frustrated that he continued to elude police.

“We don’t know where he is,” regional police chief Josep Lluís Trapero said at a news conference in Barcelona, adding that the terrorist cell had planned a “much more serious attack” that probably was thwarted by an accidental explosion Wednesday at a house used to assemble components for a bomb.

Authorities said Sunday that they had identified three more victims in the Barcelona attack, including Julian Cadman, a 7-year-old boy with dual British and Australian citizenship who had been missing since Thursday. He was separated from his family in the panic unleashed by the attack and was struck by the speeding van.

One American, Jared Tucker, 42, a father of three, was earlier identified as a victim. He was killed while on his honeymoon.

What we know about the two vehicle attacks in Spain

Inspector Albert Oliva, the chief spokesman for the Catalan national police, stressed that the cell made up of 12 teens and young men — most of them of Moroccan descent from Ripoll, a picturesque mountain town near the French border — were dead, arrested or in hiding.

In an emotional plea on Spanish television, the mother of Abouyaaqoub, the main missing suspect, begged her son to turn himself in. 

“I prefer him going to jail to him dying,” Hanno Ghanim, the mother, said.

Police kept a close eye on the streets of Ripoll on Sunday, on the lookout for Abouyaaqoub and others. Officers were parked outside the family homes of the men suspected of being in the cell.

Abouyaaqoub’s mother was hospitalized Sunday, suffering from stress, family members said. Abouyaaqoub’s aunt told The Washington Post that “someone brainwashed them. This has destroyed our family. We are devastated. We don’t understand what happened.”

Catalan police officials say they have no concrete information about how the cell members were radicalized and recruited — nor how they plotted their attacks and kept their secrets in a close-knit community of Moroccan immigrants.

The consensus among family members in Ripoll was that the young men fell under the sway of a charismatic cleric who had possibly turned their sons, brothers and cousins toward violence.

All eyes in the Spanish media are on a suspect named as Abdelbaki Essati, who was employed at a mosque in Ripoll and whose home was searched Saturday. Police said Sunday that Essati had not been connected to previous terrorism-related investigations but that an unidentified friend of his had been implicated.

At the small storefront mosque in Ripoll, a handwritten list of members posted on a bulletin board includes several of the names tied to the terrorist cell.

Ali Yassine, the director of the mosque, said Essati was paid about $1,000 a month to serve as imam. Local benefactors paid his rent and helped with groceries.

As part of his duties, Essati taught younger children the Koran, the Arabic language and religious practices. He had worked at the mosque for the past 18 months and had been in the town for about two years.

“He was a normal man, normal, you understand?” said Yassine, whose eyes welled with tears as he spoke. “That is all I can tell you. He did not preach hate. He did not recruit in the mosque.”

“He was teaching my own sons,” ages 7 and 8, Yassine said. “Do you think we would allow him to teach our kids to kill? We all have families here.” 

Essati, an immigrant from Morocco, told people in Ripoll he had a wife and nine children back home.

Members of the mosque said that Essati’s name was given to local police more than a year ago as part of a security protocol to keep a closer eye on Muslim preachers, and that authorities did not flag him.

A close relative of the Hychami brothers, Mohamed and Omar, who were members of the cell and are now believed dead, said the Muslim cleric would often drink mint tea in a Moroccan cafe by the local train station. 

“In his sermons, he would talk about how we should all live in peace, how the Moroccans here should work hard and be thankful to the Spanish people for their hospitality,” said the relative, who spoke on the condition of anonymity because he has to keep living in Ripoll after the media attention fades.

“Did he show us just one face?” he asked. “Did this son of the devil take the best kids in Ripoll and turn them?”

After the end of the Muslim holy month of Ramadan in June, the cleric told mosque leaders that he wanted to take three months for vacation. They said no, that they needed him, but the preacher insisted and left town in July. He has not been seen since.

Police searched his empty apartment Saturday.

Spanish authorities said Sunday that they believe the Islamic State’s claimed connection to last week’s violence is real. However, the extent of the militant group’s involvement in the planning of the attack remains unclear. 

After its initial claim of responsibility, the Islamic State published an expanded statement Saturday that contained factual errors. Such mistakes are not uncommon and should not rule out an Islamic State connection, security analysts said.

The department’s “thesis,” Trapero said, is that the cell had planned a much more serious attack but had to abandon that after the accidental explosion. 

Trapero said that on Thursday, the attackers used only one van, with a single occupant, in Barcelona. He noted that police have since recovered three rented vans in connection with the attack there, as well as an Audi A3 used in the nearby town of Cambrils and a motorcycle. Searches of the vehicles have produced “positive results,” he said.

In Barcelona, police were ubiquitous Sunday, even as Carles Puigdemont, the president of Catalonia, said the city had “rejected terrorism.”

“Normality has come back to Las Ramblas,” Puigdemont said to reporters, “and we are rejecting openly any sign of xenophobia or radicalism.”

Although the Spanish media has paid much attention to the Moroccan origins of the suspects, Puigdemont was careful to defend the minority group, which numbers about 200,000 in the region. 

“The Moroccan people are integrated in Catalonia,” he said, “and they have made important contributions to the community.”

Prime Minister Mariano Rajoy and King Felipe VI attended a memorial Mass at Barcelona’s famous Sagrada Familia Basilica. Pope Francis relayed a message of condolence, expressing “deep regret” at “such an inhuman action,” referring to the attacks.

McAuley reported from Barcelona. Angel Garcia and Raúl Gallego Abellan contributed to this report.