Explosive weapons generally use high explosive to project blast and often fragmentation from a point of detonation. Explosive weapons may be subdivided by their method of manufacture into explosive ordnance and improvised explosive devices (IED). Certain types of explosive ordnance and many improvised explosive devices are sometimes referred to under the generic term bomb. When explosive weapons fail to function as designed they are often left as unexploded ordnance (UXO). In armed conflict, the general rules of international humanitarian law apply to attacks with all types of explosive weapon.