A security guard was shot dead in Rosebank on Friday afternoon.

This is after he saw four suspects attempting to rob a man who was walking on the side of the road, police spokesperson Lungelo Dlamini told News24.

"A man was walking on the street when he was approached by four suspects who wanted to rob him," Dlamini said.

Dlamini said the security guard saw what was happening and approached to help.

He added that when the guard approached the suspects, a shootout occurred.

One suspect was wounded but was helped by the three other suspects into a vehicle which then drove away.

The incident took place on the corner of Baker and Oxford streets.

He added that a firearm belonging to one of the suspects was found on the scene and had been taken by the police.

A case of murder and armed robbery has been opened, Dlamini added.

He said the security guard had not yet been identified by his family and a search for the suspects continues.