Here's some of the account...
SA National Defence Force spokesman brigadier general Kwena Mangope says the cause of the malfunction is not yet known...So much for Asimov's Three Laws of Robotics :-(
Media reports say the shooting exercise, using live ammunition, took place at the SA Army's Combat Training Centre, at Lohatlha, in the Northern Cape, as part of an annual force preparation endeavour.
Mangope told The Star that it “is assumed that there was a mechanical problem, which led to the accident. The gun, which was fully loaded, did not fire as it normally should have," he said. "It appears as though the gun, which is computerised, jammed before there was some sort of explosion, and then it opened fire uncontrollably, killing and injuring the soldiers."
Other reports have suggested a computer error might have been to blame. Defence pundit Helmoed-Römer Heitman told the Weekend Argus that if “the cause lay in computer error, the reason for the tragedy might never be found."
Or maybe not...
"Please put down your weapon. You have twenty seconds to comply."