A majority of the suspects in the Barcelona attacks are from the small mountain town of Ripoll, in northern Spain. Among the suspects are two brothers, Said and Yousseff Aallaa. (Raul Gallego Abellan/The Washington Post)

Two days after a devastating vehicle attack on one of Europe’s most iconic tourist destinations, many questions remained as Spanish authorities continued a manhunt for a 22-year-old missing member of the cell of suspected terrorists responsible for the brutal assault that killed 14 and injured more than 100 others.

Unlike other vehicle attacks Europe has endured in the last two years — in Nice, Berlin, Stockholm and London — Thursday’s in Barcelona and the one early Friday in the nearby seaside city of Cambrils displayed an unusual degree of sophistication and coordination. Authorities are investigating what they believe to be a terrorist cell of at least 12 members with possible bases in different locations across the region of Catalonia.

But the Spanish government was quick to insist on Saturday that the situation was under control. Interior Minister Juan Ignacio Zoido Álvarez said that the 12-person cell had been “dismantled,” and the government ultimately declined to raise the national alert level from four to five, the highest-possible classification.

Inspector Albert Oliva, chief spokesman for the national Catalan police, said the local police force spearheading the investigation here, however, cast doubt on the government’s proclamation. “We must remember who is the leader of the investigation,” he said in a news conference, highlighting the work that remains to be done. Oliva then said that police home raids had failed to produce the missing suspect. When asked about the potential for another attack still to come, he said the prospect was unlikely but could not be deemed impossible.

Police in Barcelona separated nationalist demonstrators from anti-fascist marchers the day after an attack killed more than a dozen people. (The Washington Post)

Although police shot dead five suspects early Friday morning and have since arrested four others, many loose ends remain.

For one, there is the rare social uniformity of the suspects’ backgrounds: Most of the 12 people identified as members of the cell come from the same small town near the French border, almost all are of Moroccan immigrant origins and all are younger than 35.

Then there are the puzzling logistics. The suspects ultimately struck three different locations in quick succession — one by accident. Propane and butane canisters that police believe the suspects intended to detonate in Barcelona exploded prematurely in the city of Alcantar on Wednesday, killing at least two and injuring 16.

On Thursday, the driver who then struck Barcelona’s most famous promenade was somehow able to escape from the scene on foot. The same suspect may then have been among the group of five that committed a second vehicle attack just hours later in Cambrils, police believe — a distance about 70 miles to the southwest.

The missing suspect is Younes Abouyaaqoub, according to Catalan police officials cited in Spanish media. Police believe he left Las Ramblas neighborhood after the attack, hijacked a car after killing the driver, and drove out of the city. Police found a dead body with multiple stab wounds in an abandoned Ford vehicle, which they believe to be connected to the attack.

Finally, there is the question of motive. Shortly after the twin attacks, the Islamic State, through its Amaq News Agency, asserted responsibility for the carnage, heralding the suspects as “soldiers.” On Saturday, however, the terrorism group issued a second, expanded statement — which ultimately contained glaring factual errors. Many security analysts interpreted the mistakes as evidence that the caliphate, in the midst of major territorial losses in the Middle East, may have been trying to overstate its influence overseas.

What we know about the two vehicle attacks in Spain

So far, the degree of real involvement by the terrorist group remains unclear. In recent months, the Islamic State has asserted responsibility for international attacks that it did not orchestrate, as investigators concluded was the case with the attack on a Manila casino in early June.

In the group’s expanded statement on the Barcelona attacks, for instance, the text notes that the attackers “stormed a bar with their light weapons near Las Ramblas square, torturing and killing the Crusaders and Jews inside.” No “bar” was stormed, the “weapon” employed in the attack was a van and victims were attacked indiscriminately rather than selected on the basis of religion or race.

For some analysts, the errors indicated that the Islamic State may not been directly involved. Others said that the group has made mistakes in the past, and has corrected them in due course, which may still be the case regarding Barcelona. Spanish investigators also reportedly uncovered traces of triacetone triperoxide (TATP), a trademark explosive of the group, while investigating the site of Wednesday’s explosion in Alcanar.

Jean-Charles Brisard, a leading security analyst and the director of the Paris-based Center for the Analysis of Terrorism, said the important point was the potential for the group to inspire future attacks even as its own territory shrinks.

“[Barcelona] states for me that the situation on the ground in Syria and Iraq is clearly disconnected from the capacity of the Islamic State and its militants abroad,” he said in an interview. “There’s no correlation between the two. What we see in Spain is specific to Spain, but it tells us that the threat is intense all over Europe.”

Barcelona and the nation beyond continued to mourn the diverse, multinational group of 14 victims — including at least one American — massacred in the heart of this city and in nearby Cambrils.

On Saturday, Spain’s king and queen visited victims of the attack in hospital, and Barcelona Mayor Ada Colau opened a book of condolences at city hall.

“We are closer than ever,” she told reporters Saturday. “I stand with all officials and citizens to condemn this terrorist attack, and we are together with all families of the victims, as well as those who remain in serious condition fighting for their lives.”

Booth, Mekhennet and Raúl Gallego Abellan reported from Ripoll, Spain. Angel Martinez in Madrid contributed to this report.