Armed men infiltrated a nuclear reactor and research facility near Pretoria and shot and wounded an employee.
The motive of the incursion last week remained unclear. Officials of the South African Nuclear Energy Corporation said they believed the raid at the Pelindaba facility - during which an attempt was made to seize a computer - was carried out by "technically sophisticated criminals" with knowledge of the facility's electronic security systems.
Six Pelindaba security officials were suspended this week.
Just after midnight on Nov. 8, four armed men cut through the outside fence and then slipped through an electric fence, the head of the corporation, Rob Adam, said in a statement Tuesday. Several security layers on the electric fence were deactivated and no alarm was triggered at the security control center.
The intruders then broke into the engine room and gained access to the emergency control center, where fire engines, ambulances and other equipment is at the ready to respond to emergencies at the facility. The intruders then made their way to the emergency center's control room, kicked opened the door and shot the station commander, Anton Gerber and assaulted an operator.
Gerber had alerted security and the infiltrators then fled the same way they gained access.
Adam said that "at no time was the emergency control room systems compromised."
Elsewhere at the plant at the same time, Adam said, a patrolling security officer spotted and fired shots at others who appeared to be trying to intrude, and who then fled without gaining access to the site.
Pelindaba, commissioned in the mid 1960s, was at the center of the apartheid's government nuclear weapons production program. It is now devoted to research, developing isotopes used for cancer treatment.
By 1991 South Africa had dismantled its nuclear weapons program, making it the first and only nation to build and then voluntarily destroy nuclear weapons.
Today, South Africa has a nuclear energy power plant with two reactors at Koeberg, on the west coast outside Cape Town.
An increasing number of African states are turning to nuclear energy as an alternative to spiraling costs of electricity and fuel, which are only going to be made worse by the problems of climate change.
However, concerns are being raised whether these countries, many of which are poor and without resources, will be able to secure such installations and not become the target of international crime syndicates.