UPDATED: A van plowed into dozens of pedestrians in Barcelona’s historic Las Ramblas district on Thursday.

Authorities said 13 people have died and 100 others have been injured after a white van jumped the sidewalk and crashed into a crowd. That death toll could rise, as at least 15 of the people hurt were seriously injured.

Hours later, a linked attack was carried out in Cambrils, south of Barcelona, by five assailants who were shot dead by police. A woman died of her injuries. The suspected driver in Thursday’s Barcelona attack, 18-year-old Moussa Oukabir, was named on Friday afternoon as one of the five men killed by police.

Authorities also said they are treating the Barcelona incident as a terror attack. “We confirm the terrorist attack,” Catalan police said. “The protocol for terrorist attacks has been activated.” The Islamic State later claimed responsibility for the incident.

President Donald Trump condemned the terror attack in a tweet on Thursday.

“The United States condemns the terror attack in Barcelona, Spain, and will do whatever is necessary to help. Be tough & strong, we love you!” he wrote.

“The United States condemns this terror attack and we will do whatever is necessary to help,” Vice President Mike Pence later added during a press conference.

Two suspects have been arrested thus far, Carles Puigdemont, the president of Catalonia, said. According to Spanish newspaper El Periodico, at least one of the suspects had been hiding in the Turkish restaurant Luna de Istanbul in the center of the city.

More than two hours after the first attack, Catalan police said a car ran over two officers at a highway checkpoint near Barcelona. It’s still unclear whether the incident was related to the attack on Las Ramblas.

And police shot dead five terrorist suspects in Cambrils early Friday after a car drove into a small group of seven people, killing one. According to police reports, the suspects were wearing explosive belts and were linked to the first Barcelona attack.

Witnesses to the initial attack in Las Ramblas said the van zigzagged down the busy Barcelona tourist destination — at the height of vacation season — mowing people down and leaving bloodied bodies sprawled on the ground as other pedestrians scrambled, in panic, toward safety.

Resident Keith Fleming told the Associated Press that he was watching TV when he heard a noise, looked out of his balcony, and “saw women and children just running, and they looked terrified.”

“I heard screams and a bit of a crash, and then I just saw the crowd parting and this van going full pelt down the middle of the Ramblas, and I immediately knew that it was a terrorist attack or something like that,” another eyewitness, Tom Gueller, told the BBC.

The tragedy follows other similar terrorist attacks across Europe, many of which involved the use of vehicles. Most recently, a man drove a car into pedestrians, killing four people, on London’s Westminster Bridge on March 22. Similar attacks have killed more than 100 people in Nice, Berlin, London, and Stockholm in the last year.

Thursday’s attack was Spain’s deadliest since 2004, when bombers killed 192 people in Madrid.

Elsa Keslassy and John Hopewell contributed to this report.