It's a hoax. This first saw the light of day under the term Uhuru - Night Of The Long Knives.
The "Night Of The Long Knives" is a fallacy doing the rounds attributed incorrectly to Siener Van Rensburg. There is no evidence of this in the recorded visions of Van Rensburg and it has been proved to be a groundless fact. The first and most glaring problem is the deliberate and incorrect translation of Uhuru which means freedom in Swahili.
The people spreading this rumour comprise perhaps 2% of a certain community - a small band of fanatics in the grip of apocalyptic fantasies who are spreading this false idea.
skeptic.za.org/ had the following to say about the logistics of the plan's execution:
" At an average of 14 people plus weapons per taxi, that's 5,000 taxis. That, in turn, is a single-file line about 25 km long. Not impossible, of course, especially if the infiltration is spread out over several hours, but highly unlikely that they should get through largely undetected. Also, consider the size of the supposed cover-up: several government departments, the police services, the army and the justice system, all of whom are expected to keep silent. There's an old saying (there always is one, isn't there?) that covers this aspect quite nicely: "Three can keep a secret if two of them are dead.""
Frik Pretorius who wrote Siener van Rensburg - profeet of waarsêer - Wat is die Waarheid? (ISBN 0-620-37153-6) has the following to say: "Please, whatever you do, don't fall for the horrible stories ascribed to this gentle old man. You would have heard stories of "a night of terror", "the night of the long knives" or "uhuru", etc. There is no evidence of this in the recorded visions and I have actually proven that this is a blatant and fabricated lie. Some people on the very far right have fabricated this information to score political points by playing on the emotions of a gullible public. Their aim is on the one hand to kickstart a rebellion, and on the other to create resistance to the visions amongst the more spiritually and politically balanced group."
Siener van Rensburg - profeet of waarsêer - Wat is die Waarheid? (ISBN 0-620-37153-6)