Two teenagers were killed and five wounded in a shooting incident in Johannesburg on Tuesday, police said, adding that they suspected the incident was gang-related.

"The teenagers were approached by four suspects on foot, three carrying firearms. The suspects opened fire at the victims without saying anything and then fled the scene," a police spokesperson said in a statement.

The victims are aged between 13 and 19 years, and those that were wounded are receiving medical attention in hospital.

Police said an anti-gang unit was on the scene along with forensic services.

South Africa has one of the highest murder rates in the world, averaging about 60 a day.