I think what we are seeing was something many people have predicted over the years: that "melt down" in law and order, when grievences turn from mere protests and brick throwing to more more serious terrorist attacks.
My personal feeling, one can draw a correlation between the terrorism of apartheid and what we are seeing now. There are some out there that perhaps feel that the only way to cure corruption is destruction; that these bombs are a message to the ANC of "things to come" if they continue down this land process against the Zulu's.
I think you and I and the ANC horribly underestimate what is to come if they annexe Zulu territory. We will have war.
Putting bombs in public places, this can never be accepted or even tolerated not in any way, shape nor form and something like this must be stamped out hard and with severe force or this will get worse.