Landmines and unexploded ordnance (UXO) are a legacy of war, insurrection, and guerilla activity. Landmines kill and maim approximately 26,000 people annually. In Cambodia, whole areas of arable land cannot be farmed due to the threat of landmines. United Nations relief operations are made more difficult and dangerous due to the mining of roads. Current demining techniques are heavily reliant on metal detectors and prodders.