Three people were killed, and two others injured following a shooting on a Tembisa street, north of Johannesburg.
The incident happened on the busy street at around 12:30 on Wednesday.
Police spokesperson Captain Kay Makhubela said the motive for the shooting was unknown and police were not sure how many suspects were involved, but three people were shot and killed.
Police said they had not established how a fifth victim had sustained injuries.
"A lady was injured and taken to hospital. We don't yet know how she was injured," he said.
Makhubela said it was "not yet clear" what caused the shooting, but it would make up part of the investigation.
"Police have opened a case of murder and attempted murder. We don't know the motive for the shooting or how many suspects there were, but we will continue with our investigations," he said.