A truck has ploughed into the upscale Ahlens department store in the Swedish capital of Stockholm on Friday, injuring people, police said.

Swedish radio said that three people have been killed in the crash and Swedish broadcaster SVT says shots have been fired.

“Police received a call from SOS Alarm that a person in a vehicle has injured other people on Drottninggatan,” police wrote on Twitter.

The incident occurred just before 1300 GMT at a corner of the Ahlens department store and the city's biggest pedestrian street, above-ground from Stockholm's central subway station.

Thick smoke was rising from the scene, but police have yet to confirm the information.

Video images showed an area blocked off by police and crowds gathering around the police cordon.

Helicopters could be heard hovering in the sky over central Stockholm, and a large number of police cars and ambulances were dispatched to the scene, witnesses said.

It was not immediately clear whether it was an accident or an attack.

In July 2016, 84 people were killed including 10 children, when a truck drove into a crowd watching a fireworks display in Nice, France, for Bastille Day.

Moreover, 12 people were killed in Berlin in December last year as 12 killed as a lorry ploughed into the crowd at a busy Christmas market.

Both attacks were claimed by the militant Islamic State group.