Four men, aged 27 to 35, were shot dead, and four people were seriously injured when gunmen opened fire on a home in Mazizini, Brown's Farm, on Sunday night.
Western Cape police spokesperson Colonel André Traut said three of the men were killed at the scene, and the fourth victim died in hospital.
Traut added that detectives attached to the provincial Serious and Violent Crimes Unit were following several leads in a bid to apprehend the perpetrators.