The attack on two parked security guards in Soweto‚ south of Johannesburg‚ was carried out by "heartless criminals with no regard for human life"‚ 24/7 Security Services said on Monday.
The two reaction officers‚ Eric Ngobese and Boykie Moyo‚ were gunned down near Maponya Mall in Soweto last week Wednesday.
The company's Geoff Schapiro told TimesLIVE the guards were "very experienced an seasoned officers".
A video of the attack was captured by a high definition camera fitted inside of the vehicle. The vehicle is also fitted with a camera on the outside.
Schapiro said the men and vehicle were deployed as part of a team providing specialised security services for a national financial institution.
A gruesome 30-second video doing the rounds on social media shows the moment the two guards are shot dead in broad daylight at what appears to be close range.
It shows their vehicle parked near Maponya Mall. Both are wearing their uniforms and bullet-proof vests. One of the guards was sitting with a book and pen on his lap‚ reading.
Moments later‚ two armed men open fire through the driver-side window‚ seemingly instantly killing him.
Shots ring out on the other side of the vehicle‚ hitting the passenger in his head.