Originally developed in World War II, the PMD-6 antipersonnelmine is a rudimentary pressure-activated blast device in a box. It has been widely used in Cambodia. As wood rots, the mine mechanism may shift, and the device often sets itself off or becomes inoperative.
The most prevalent of the conventional landmines are the so-called blast mines. They rely upon the energy released by the explosive charge to harm their target, and are normally buried by hand or placed on the ground. It's large explosive content (240 grammes of TNT), is often fatal.
It has probably killed and maimed more civilians than any other type of mine. It is deployed in vast numbers in Afghanistan, Cambodia, North Iraq/Kurdistan, Iran, Nicaragua, Angola, Mozambique and many other countries.
The injuries they produce result from the explosion, but secondary fragmentation injuries are possible as the mine casing or surrounding dirt or gravel is blasted at the victim. Most depend on blast alone for their effectiveness, since the target generally needs to come in contact with the mine to set it off.