The victim was taken to the city’s Vrinnevi Hospital from his store in the Hageby district but doctors were unable to save his life.
Police have launched a murder investigation.
“We are looking for two suspected perpetrators, a woman aged around 25 and a man of around 40,” police spokesman Anders Månsson told news agency TT.
Witnesses saw the pair fleeing towards the city centre after the attack. The woman had dark, shoulder-length hair and was wearing a mid-length coat. The man was described as well-built and balding with dark hair.
Police have not established a motive for the attack.