Police in central Sweden have increased security at refugee accommodation centres after two Eritrean asylum seekers were arrested on suspicion of murdering two people at an Ikea store.
Local officials feared a backlash from “dark forces” who wanted to exploit the case, police chief Per Agren said.
A mother and son died in the knife attack which took place inside an Ikea store in Vasteras on Monday.
The store has temporarily stopped selling knives following the killings.
It re-opened on Wednesday and manager Mattias Johansson said he hoped staff and customers could return to “as normal a day as possible”.
Security around the store was stepped up, while police officers also strengthened surveillance at refugee camps in the region, including at the centre where the two suspects live.
Officers were called to the Ikea in the Eikslund shopping centre at 13:00 (11:00 GMT) on Monday and found three people with knife injuries in the kitchenware section, police spokesman Per Stromback said after the incident.
A mother and her adult son – described as “ordinary shoppers” – died at the scene. A 35-year-old man found seriously injured was linked to the attack, reports say.
Police confirmed on Tuesday morning that they had arrested two men from Eritrea who lived in asylum accommodation in the city of Arboga.
The youngest suspect, 23, had been questioned and denied the attack, police said. The second man remained in hospital with life-threatening injuries and had not yet been interrogated.
‘Act of madness’
The motive for the attack is unclear, but police said there were no political overtones.
“It is an act of madness,” Mr Agren was quoted as saying.
Ikea has not confirmed whether knives on sale were used in the stabbing.
The store in Vasteras, which is about 70 miles (115km) west of the capital Stockholm, is one of the largest in the country.