Two men suspected of involvement in the truck attack that killed four people in Stockholm have been arrested, Swedish media reported.
Swedish PM said "Sweden has been attacked, everything indicating it is an act of terrorism."
Swedish broadcaster SVT says shots were fired at the scene and the Swedish news agency TT says several people have been rushed away in ambulances.
Live television footage on Friday showed smoke coming out of the upscale Ahlens department store on Drottninggatan Street, which the truck smashed into. The department store is part of Sweden-wide chain. The building includes several stores at street-level.
Police said the first man arrested in a Stockholm suburb resembled the picture and description of a man that police went public with after the attack. The second suspect was arrested separately in a Stockholm suburb later in the night.
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.
“We stood inside a shoe store and heard something ... and then people started to scream,” witness Jan Granroth told the Aftonbladet daily. "I looked out of the store and saw a big truck."
Swedish police confirmed that a truck drove into people and the store but could not confirm the reports of shots fired. Police said in a statement “there are reports of injured but we have no details on how many and how serious.”