Four people were killed and three others injured in a minibus taxi rank shooting in South Africa's legislative capital Cape Town on Friday.

The incident occurred at the old taxi rank in Mfuleni, 30 kilometres (19 miles) east of the city centre at about 6am, according to a statement from Western Cape provincial police spokesperson Novela Potelwa.

"Of the seven victims, one injured is believed to be a commuter," Potelwa said, adding that the police had bolstered deployment as Friday's incident was under investigation.

Potelwa said a 100,000 South African rand (more than $5,000) bounty was available to anyone with information on the shooting and that any detail received would be handled with care and whistleblower identities protected.