The nail bomb is an anti-personnel explosive device packed with nails to increase its wounding ability. The nails act as shrapnel, leading almost certainly to greater loss of life and injury in inhabited areas than the explosives alone would. The nail bomb is also a type of flechette weapon. Such weapons use bits of shrapnel (ball bearings, nail heads, broken razors, darts and bits of metal) to produce a large radius of destruction.
Nail bombs are often used by terrorists, in particular by suicide bombers, since they cause large numbers of casualties when detonated in crowded places. Nail bombs can be detected via electromagnetic sensors and standard metal detectors.
On March 6, 1970, in the Greenwich Village townhouse explosion, three members of the Weather Underground were killed in the accidental explosion of a nail bomb intended to be set off at a non-commissioned officers dance at the Fort Dix, New Jersey Army base.
On 29 June 2007, a nail bomb that was assumed to be a part of a terror plot was discovered in a Mercedes car and was consequently defused by police in the West End of London. There was a second car bomb, further down the street that was apparently scheduled to detonate as evacuees and survivors fled down the street, to a nearby tube station. It is probable this bomb was also a nail/shrapnel device.
On 21 December, 2007, a nail bomb was detonated in Sherpao, Pakistan by a suicide bomber. Detonation occurred inside a tightly packed mosque, filled with holiday worshippers. At least 50 people were killed, with over 100 injured.
On 22nd May 2008 a nail bomb explosive was detonated in the toilets of Giraffe cafe in Exeters Shopping Centre, Princesshay in Devon. The homemade bomb exploded in the attacker's face as he was trying to ready it in the cafe toilet. Police then found another nail bomb inside the cafe after everybody had been evacuated.