Manhunt under way as cops release picture of 'person of interest'
Several people have died and more have been injured after a terror attack which saw a lorry plough into pedestrians in Stockholm.
Police issued an image of a man they want to trace in connection with the outrage in a busy shopping district in the centre of the Swedish capital.
Two people are currently being questioned by police, but spokesman Lars Bystrom added: "That doesn't mean they are suspects."
Prime Minister Stefan Lofven said the incident appeared to have been "a terror attack" as police said the driver of the truck had fled.
Despite earlier reports and pictures on social media, a police spokesman said there had been no arrests, adding: "For the moment police are searching for a person or persons."
The lorry ploughed into the corner of a department store and burst into flames.
Broadcaster SVT reported that at least five people had been killed. Other Swedish media reported the toll to be at least three.
At a press conference national police commissioner Dan Eliasson said: "A truck was driven into Ahlen's department store on Drottninggatan. There are many people injured.
We can't confirm numbers of injuries or deaths at this press conference. The medical authorities will confirm that."
"We have no contact with the person or persons who drove the truck," he added.
Senior police officer Mats Lofving said: "We don't know whether this incident is isolated or whether we can expect more.
"We have police positioned at several strategic places with a particular risk threat."
Mr Lofving showed pictures of the man they want to speak to, urging anyone with information to get in touch and saying: "For us it's important to get in touch with this person."
Widespread condemnation poured in from across the globe as news of the attack broke, including from German Chancellor Angela Merkel and Foreign Secretary Boris Johnson, who said he was "deeply concerned".
President of the EU Commission Jean-Claude Juncker said: "An attack on any of our Member States is an attack on us all."
The incident comes after trucks 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.
The Aftonbladet newspaper reported that the truck had been hijacked from Swedish beermaker Spendrups earlier on Friday.
The lorry smashed through stone lion bollard into the pedestrianised area, leaving a trail of blood and debris.
Witness Jan Granroth told Aftonbladet that "we stood inside a shoe store and heard something ... and then people started to scream." He said: "I looked out of the store and saw a big truck."
Another witness quoted by the paper said: "When I came out, I saw a lorry standing there, with smoke coming from it, and there were loads of bits of cars and broken flower pots along the street."
Mikael Anttila, a 49-year-old portfolio manager at bank SEB, told the Press Association he saw several hundred people gathered on the street close to the shop, before they all started running "suddenly ... like ants".
"Then a lot of police started coming. Heavy weapons, civilian police, etcetera," he said.
Annevi Peterson described people lying dead and injured in the street, with blood everywhere.
"I heard the noise, I heard the screams, I saw the people," she told BBC News.
"There was, just outside the store, there was a dead dog, the owner screaming, there was a lady lying with a severed foot.
"There was blood everywhere, there were bodies on the ground everywhere.
"There was a sense of panic, people standing by their loved ones, but also people running away."
The crash is close to the scene of a terror attack in 2010 when Taimour Abdulwahab, a Swedish citizen who lived in Luton, blew himself up.
The terrorist, who police concluded acted alone, died on December 11 2010 in the Bryggargatan area. No one else was killed.
Abdulwahab rigged an Audi car with explosives in the hope that the blast would drive people to Drottninggatan, a busy shopping street, where he was waiting to set off two more devices strapped to his chest and back.
The car bomb never went off and, after setting fire to the Audi, he was unable to detonate the other two explosives as planned.
He made his way down a side street off Drottninggatan and, in an apparent attempt to fix the faulty trigger up his sleeve, set off the bomb on the front of his body, killing only himself.