A manhunt is underway in Sweden after a lorry ploughed into crowds in a shopping area in central Stockholm killing at least three people and leaving several injured.
Armed police rushed to the scene but the driver of the vehicle fled.
Sweden’s intelligence agency has said there was a “large number injured” in the attack.
Stefan Lofven, the Prime Minister, said all evidence pointed to “a terror attack”.
Victims were covered with blankets while bloodstains could be seen on pavements near the lorry, which was left halfway inside a well-known department store on Drottninggatan (Queens Street), with its cab on fire.
The lorry, which had been hijacked from the Spendrups brewery earlier in the day, hit pedestrians before crashing into Ahlens Mall.
“I went to the main street when a big truck came out of nowhere," a witness told Sweden's Aftonbladet newspaper.
"I could not see if anyone was driving it but it got out of control. I saw at least two being run over. I ran as fast as I could from there.”
Witness Jan Granroth told reporters: “We stood inside a shoe store and heard something... and then people started to scream.”
Another witness told the paper they saw hundreds of people “running for their lives” outside the shopping centre.
Police said they could not confirm any arrests, but said they were hunting for a suspect described as wearing a green jacket, grey hoodie and white shoes.
All public transport in the capital has been closed down and police have ordered the evacuation of Stockholm's central train station.
Police could not confirm multiple reports that shots had been fired nearby, as Facebook's "safety check" feature was activated for residents.
The attack comes after lorries were used in terror attacks in Nice and Berlin last year and just two weeks after Muslim convert Khalid Masood ploughed his car into pedestrians on Westminster Bridge in London.
Those atrocities have been linked to Isis but there was no immediate claim of responsibility from the group over Stockholm.
The Stockholm attack is close to the scene of an attempted bombing in the capital in 2010, in which an attacker blew himself up. No one else was killed.
