An Eritrean who is the primary suspect for the stabbing to death of two people at an Ikea store in Sweden had received a deportation order to Italy hours before he went on the rampage, according to the Swedish migration agency.

The man, a 35-year-old who had been living in an asylum centre in Vasteras, had met migration officials to discuss his case before the attack, which killed a 55-year-old Swedish woman and her 28-year-old son in the local Ikea furniture store.

"There was a decision to extradite him to Italy where he already had residency," agency spokesman Fredrik Bengtsson said. The Eritrean application for residency was rejected on 16 July.

Article 8 of the Dublin Convention establishes that asylum seekers travelling to the European Union are not free to choose in which state to lodge an asylum application. Instead, the state whose territory he or she enters is responsible. Migrants can be sent back to their first point of entry to the European Union.

Swedish police also detained a 23-year-old man who was staying at the same centre as the attacker, who was found at the scene with serious knife injuries.

CCTV cameras show the suspect grabbing two knives from Ikea's kitchenware section before attacking the two shoppers. "The attack ends when the alleged murderer stabs himself in the stomach," a report on Swedish newspaper Aftonbladet said.

Swedish police have been unable to interview the man because of his critical conditions. They added that they did not believe the attack was politically motivated.