A hijacked beer truck plowed into pedestrians in the center of Stockholm on Friday, killing four of them and injuring at least 15 others — nine of them seriously — as hundreds more ran in fear.
Swedish Prime Minister Stefan Lofven labeled the incident a terrorist attack.
"Sweden has been attacked," Lofven said, asserting that everything indicates that this was a terrorist attack.
Swedish police released a photo of a man they wanted to question in connection to the incident, and reported he was still at large Friday afternoon. But later, Swedish media reported an arrest had been made.
The grainy image shows a man in a hoodie stepping off an escalator. Swedish police also said they were questioning two people but they were not necessarily suspects.
The dead and injured lay in the pedestrian area as shoppers and office workers ran for their lives. Swedish media, citing police at the scene, reported that three people were dead and at least eight injured, but authorities would not confirm the figures and only said that a large number of people had been injured. Later, the death toll was officially increased to four dead and 15 injured.
Images from the scene appeared to show several bodies covered in orange blankets as medical workers rushed around.
Photographer Annevi Petersson told the BBC there was a sense of "sheer panic" as events unfolded in Drottninggatan Street (Queens Street), a busy, pedestrian area in central Stockholm, shortly before 3 p.m. local time.
"There were bodies on the ground everywhere and the scene of panic," she said. "People were standing by their loved ones but also people were running away, mainly to the minor streets.... It got very quiet. There was the noise and then everything got quiet, and then people started screaming and crying — obviously people severely wounded."
The vehicle belonged to brewery company Spendrups and had been stolen earlier in the day outside a restaurant in central Stockholm by a man who jumped in the cab and drove off. The company said in a statement that the driver tried to stand in front of the truck to stop the hijacker from driving away, but had to throw himself to one side to avoid being run over.
"He is slightly injured but obviously shocked by the incident," the company said. A short while later, the truck reportedly plowed into a crowd of people and then struck the Åhléns department store, where it came to a halt. Images on television showed black smoke billowing into the sky as the cab appeared to catch fire.
Jan Granroth was on Drottninggatan Street when he heard screams. "We were inside a shoe store, and we heard a noise, and people started screaming," he told the Aftonbladet newspaper. "So I looked out from the store to see a huge truck slam into the wall opposite."
The nearby Swedish parliament was placed on lockdown and the metro was shut down. Bus services were severely disrupted and all train services into and out of Stockholm's main station were canceled. Shoppers were locked inside the stores for several hours, and residents outside the impact zone were told to stay home.
"I encourage everyone to be vigilant and to pay attention to the information from the police," Lofven said. Police clad in riot gear and carrying weapons swarmed the area and helicopters were seen overhead.
There were also unconfirmed reports of shots in a different part of the city, but the police denied these at a news conference. They said there had been no prior warning about an attack and were unable to say whether this was a lone wolf attack or something more coordinated.
"We do not know if it is a single event, or if we can expect more," said Mats Lofving, head of the Swedish police's National Operations Department.
Europe's leaders were quick to condemn the attacks and express their solidarity with the people of Sweden. "One of Europe's most vibrant and colorful cities appears to have been struck by those wishing it — and our very way of life — harm," Jean-Claude Juncker, president of the European Commission, said in a statement. "We stand shoulder to shoulder in solidarity with the people of Sweden."
The continent has had to deal with a spate of similar attacks in recent years. In July 2016, a truck plowed into crowds celebrating Bastille Day on the Promenade des Anglais in Nice, France, killing 86. Another man drove a truck into shoppers at a Berlin Christmas market last year. And just two weeks ago, a man drove a car into pedestrians crossing Westminster Bridge in central London, killing five people including a police officer who was standing guard outside the Houses of Parliament. The assailant was shot and killed by police.