Many readers of this site will recognize the tactic: North Korean infiltrators plant a booby trap around a fence gate used by South Korean forces inside the DMZ, about 1,440 feet south of the MDL. One ROK NCO lost his legs in the initial blast, a second sergeant lost his leg trying to assist the first victim.
South Korean officials claim this is the first such attack using box mines since 1967, reports the NY Times (click on the picture above for the story), so the ROK soldiers may have been less than vigilant about checking their patch for mines (a process many of our readers will recall).
South Korea reports its investigation [assisted by its US and other allies on the UNC] reveals the mines were placed recently and not deposited there by natural forces such as soil drift or flooding. [Remarkably, the Times reports claims by both Korea governments that infiltration of the DMZ stopped "in the 1970s," a falsehood even a quick search of the Times own clippings would likely reveal.]
The South Korean military promised "severe retaliation" for the attack, which so far appears to be the resumption of South Korean propaganda broadcasts into the DMZ (another memory for many readers of this site); see the CNN report here. The South Korean loudspeakers were shut down years ago, and North Korea has threatened to attack them if they start up again.
To learn more about mines in the Korean DMZ and their status in the Obama Administration's effort to bar use of mines by the US military, see our report here.