A man who was allegedly attacked by three robbers at an ATM near Oriental Plaza in Mayfair‚ Johannesburg‚ opened fire on his attackers‚ killing one of them on Sunday‚ said police.

Captain Mavela Masondo said the man had just put his card into the ATM machine and was yet to put in his pin when the three suspects approached him.

"He then took out his firearm and shot at them. One was killed at the scene while the other two were taken to hospital under police guard‚" said Masondo.

Police have since launched an investigation into the matter.

Masondo said it was not immediately clear whether the firearm used to shoot the robbers was legal.

"That will all form part of our investigation‚" he said.