Security guards protecting a diplomat are under investigation for attempted murder after they shot and wounded an alleged robber in Pretoria.

A graphic video - which has gone viral - shows the diplomat and his entourage attempting to drive off shortly after the man‚ who was armed with a knife‚ was shot in Du Toit Street on May 25.

Police spokesman‚ Colonel Lungelo Dlamini‚ said a case of attempted murder was under investigation.

"Those who shot the knife-man were security guards for the diplomat. They were confronted by the man who they shot in the upper body‚" he said‚ declining to identify the diplomat's nationality.

He said the wounded man was taken to hospital.

In the nearly two minute video‚ a woman can be heard screaming loudly as spectators gather around the wounded man who is lying bleeding in the road‚ with a blue-handled knife in his hand.

A man‚ with a foreign accent‚ who is standing next to a white Land Rover Discovery with red diplomatic number plates‚ attempts to explain that the wounded man had attacked him.

"He just attacked me with a knife‚ he just attacked me with a knife‚" he says before getting into the backseat of the car.

As he gets into car‚ the driver pulls off‚ causing bystanders to scream at the occupants to stop‚ while others call for an ambulance and police.

Pedestrians scream at those inside the car while others take photographs of the vehicle and its number plate.

"This guy is a human being - you can’t drive off‚" says a woman who films the diplomat and his security detail trying to drive off.

Other bystanders can be seen surrounding the vehicle.

It’s unclear from the video whether the driver of the car managed to drive off.

Dlamini‚ asked if the wounded man had died‚ said he had no further information on his condition.

"The investigators are still busy with the case‚" he said. 

WARNING: Graphic content - not for sensitive viewers