A gang of four men entered a grocery store in Harding last week Friday pretending to be employees – they were wearing uniforms.
They produced firearms and demanded cash.
Police spokesman Captain Petros Mpinge said one of the robbers was distracted getting keys which were with the security guard.
The panic button was activated by a staff member, causing the men to flee.
According to a statement by Maser Security, information was received by its control room indicating the panic alarm activation at the store.
Maser Security reaction officers responded and, on arrival at the scene, came under fire from the robbers outside the shop.
They returned fire and the men fled the scene in a silver VW Polo Classic.
Mpinge said shots were fired and one robber was fatally wounded.
Back-up was requested and Harding Saps responded.
Maser officers and Saps members were able to arrest one of the men.
He was found in possession of one firearm, with a round in the barrel.
The others fled towards the N2, on foot. A search was conducted but to no avail.