Unexploded ordnance
Unexploded ordnance (UXO, sometimes abbreviated as UO) and unexploded bombs (UXBs) are explosive weapons (bombs, shells, grenades, land mines, naval mines, cluster munition, and other munitions) that did not explode when they were deployed and remain at risk for detonation, sometimes many decades after they were used or discarded. When unwanted munitions are found, they are sometimes destroyed in controlled explosions, but accidental detonation of even very old explosives might also occur, sometimes with fatal consequences.