The attacks in Barcelona and Cambrils, Spain, were the work of a large Islamic terror cell made up of at least 11 members who all managed to remain under the radar of Spanish police and counterterrorism authorities.

The driver of the van who killed 13 people in Barcelona, believed to be the leader of the cell, is still at large.

From what we know so far, it appears that all the suspects evaded suspicion and that the existence of a bomb factory in Alcanar, just south of Barcelona, came as a complete surprise to Spanish police.

Fox News:

Mossos police confirmed to Fox News Saturday that Younes Abouyaaqoub, 22, a Moroccan native, was believed to still be at large and was the driver of the van that carried out the vehicle attack in a Barcelona street filled with tourists and shoppers. He is also the presumed leader of the Islamic extremist cell that carried out the attacks. Early Saturday morning, police searched two buses in northwest Catalonia in the hunt for any remaining members of the cell. Nothing was found in the searches in Girona and Garrigas, police tweeted. Spanish Interior Minister Juan Ignacio Zoido has declared that the cell was effectively broken after five members were killed, four were in detention and as many as two were killed in a previous explosion. That leaves only one remaining member: Abouyaaquoub.

But, according to police, at least three suspects are still at large.

Police announced that four people were currently in custody and three suspects, including Abouyaaquoub, are on the loose. All the suspects hail from Ripoll, a quiet, upscale town of 10,000 about 100 kilometers (62 miles) north of Barcelona. A French security official also confirmed Spanish police are looking for a Kangoo utility vehicle rented by suspects in the Barcelona attacks that may have crossed into France.

Rented houses, several vehicles, explosives, automatic weapons — this stuff costs money. And if, as the authorities claim, the attacks were a “long time” being planned, someone had to pay the terrorists’ expenses. This could not have been cheap in the “upscale” town of Ripoll.

Coordinated attacks carried out with at least some sophistication and the dedication of the terrorists to sacrifice their lives strongly suggest an al-Qaeda or ISIS operation. Right in the middle of a major European country and unbeknownst to authorities, at least 11 terrorists spent months plotting to kill a lot of Spaniards.

How is this possible?

Previous terror attacks in France and Belgium were carried out largely by terrorists authorities knew were in the country and who had been flagged for surveillance. But Spanish police had no clue these guys were in their country and plotting to do harm until that van plowed into the crowd.

If I were a Spanish citizen, I would be asking some tough questions of my government about the effectiveness of their counterterrorism efforts.