Police spokesperson Captain Joe Wilson said the unidentified assailant then insisted that the shopkeeper open the door, adding that the killer attacked the Somali when he obliged.

Police said the suspect hit his victim on the left side of the chest with a knife after which six other men joined the killer in looting the shop and bolted. They left with unspecified quantity of cell phones’ airtime and cigarettes.

Wilson said two assistants in the shop were left unhurt. Police said the four arrested suspects are aged 22, 23, 24 and 38. They would be arraigned before court on January 4 for charges of robbery and murder.

South Africa, with a population of more than 44 million, officially has nearly 30,000 refugees and 100,000 asylum seekers but unofficially there are believed to be more than five million illegal immigrants in the country.

AfricaNews reporter said the refugees have not always been welcomed in South Africa, especially in poorer black communities, since they are seen as competing for the same scarce resources and jobs.

Township businessmen, who are alleged to be directing the attacks, claim the Somalis are attracting their customers by offering cheaper prices and forcing them to shut down shops.