Swedish police says two suspects arrested after a deadly knife attack at an Ikea store in central Sweden were born in Eritrea and live in a nearby asylum center, adding the motive for the stabbing remains unknown.

Police spokesman Per Agren says it seems there was "no political reason involved" and that the men didn't know the victims, a 28-year-old Swedish man and his 55-year-old mother.

Agren told reporters on Tuesday the suspects were unknown to the police and declined to give details of Monday's attack in the central Swedish city of Vasteras.

A 23-year-old man has denied the stabbing while the other, aged 35, has not been questioned yet because he had undergone surgery, likely related to the attack. Police did not identify the suspects or the victims.