Police in Sweden have arrested two men after a lorry crashed into a Stockholm department store on Friday, killing at least four people.
The first man to be arrested is being held on suspicion of committing a terrorist crime by murder.
He was detained on Friday evening, after police released a grainy CCTV image of a person of interest, with a second arrest reportedly made later.
Swedish Prime Minister Stefan Lofven has called it a terrorist attack.
More than a dozen people were injured. Eight adults and a child remain in hospital.
The country’s borders have been tightened at the prime minister’s request.
The lorry crashed into the front of Ahlens department store in the middle of the afternoon on Drottninggatan (Queen Street), one of the city’s major pedestrian thoroughfares.
The beer company that owns the vehicle said it was hijacked outside a nearby restaurant, where it was making a delivery.
Police shared the image of the man, dressed in a hooded jacket, early on Friday evening.
They confirmed a man resembling him was arrested in Marsta, 40km (25 miles) north of Stockholm.
“We have investigated several people this evening, who we found interesting in one way or another, and recently we arrested someone we are very interested in,” said police investigator Jan Evensson, referring to the Marsta arrest.
He is being held on suspicion of committing a terrorist crime, the state prosecutor’s office said, and is in prolonged detention, according to a police website.
The second man, detained in the Hjulsta in the north-west of Stockholm, had links to the man arrested in Marsta, local media reported citing police sources.
Central Stockholm was in lockdown after the incident.
In the immediate aftermath, shoppers took refuge in nearby buildings for hours, waiting for the area to be secured.
The central station, which is near the Ahlens store, was evacuated.
The metro, central roads and various bus lines were also shut.
City authorities made several spaces, including a number of schools, available as temporary accommodation for those who could not get home because of transport disruptions.