Gauteng police have launched a manhunt for three suspects who allegedly killed a woman during an armed robbery in Roodepoort, west of Johannesburg, on Tuesday.

"Preliminary investigation revealed that the victim was in a taxi when three men stopped the taxi at the Main Reef Road traffic circle to ride as passengers," said police spokesperson Capt Kay Makhubele.

"A few minutes later, as the taxi was driving along next to old Roodepoort mine, the driver demanded payment[from the suspects]. Instead suspects took out a firearm and shot the driver and the woman, who died at the scene."

Other passengers were robbed of their belongings. The taxi driver was taken to hospital.

"Police are appealing to any member of the public who might have witnessed the incident or who has information that can help in the investigation to please call Crime Stop on 08600 10111 or via MySaps app. Callers can remain anonymous," added Makhubele.