Stockholm car-ramming suspect arrested, four dead
The main suspect, who has not yet been named and has admitted responsibility, is a 39-year old man from Uzbekistan, the Swedish newspaper, Aftonbladet, reports.
The man was arrested at Märsta railway station and had posted a number of videos in support of Islamic State on his Facebook page.
A truck crashed into the front window of the Ahlens department store on Drottninggatan (Queen Street) at around 15:00 local time (13:00 GMT).
The police launched a citywide manhunt after the attack and urged the general public not to post any rumours on social media.
"We will do everything in our power so those behind this are held responsible," said national police chief, Dan Eliasson.
The attack is being treated as a terrorist attack according to an announcement by the Swedish Prime Minister Stefan Lofven.
|Click to enlarge: A picture of the main
suspect [Source: Stockholm police]
"Police received a call from SOS Alarm that a person in a vehicle has injured other people on Drottninggatan," police wrote on Twitter.
Witness Jan Granroth told local daily news outlet Aftonbladet "we stood inside a shoe store and heard something ... and then people started to scream. I looked out of the store and saw a big truck."
Video images showed an area of Stockholm sealed off by police and crowds gathering around the cordon.
Helicopters were hovering in the sky over central Stockholm, and a large number of police cars and ambulances were dispatched to the scene, according to witness reports.
It was not immediately clear whether it was an accident or an attack.
Agencies contributed to this report