Collar bomb

An improvised explosive device (IED) is a bomb constructed and deployed in ways other than in conventional military action. It may be constructed of conventional military explosives, such as an artillery round, attached to a detonating mechanism. IEDs are commonly used as roadside bombs.

IEDs are generally seen in heavy terrorist actions or in asymmetric unconventional warfare by guerrillas or commando forces in a theatre of operations. In the second Iraq War, IEDs were used extensively against US-led invasion forces and by the end of 2007 they had become responsible for approximately 63% of coalition deaths in Iraq. They are also used in Afghanistan by insurgent groups, and have caused over 66% of coalition casualties in the 2001–present Afghanistan War.

IEDs were also used extensively by cadres of the rebel Tamil Tiger (LTTE) organisation against military targets in Sri Lanka.

An IED is a bomb fabricated in an improvised manner incorporating destructive, lethal, noxious, pyrotechnic, or incendiary chemicals and designed to destroy or incapacitate personnel or vehicles. In some cases, IEDs are used to distract, disrupt, or delay an opposing force, facilitating another type of attack. IEDs may incorporate military or commercially sourced explosives, and often combine both types, or they may otherwise be made with homemade explosives (HME).

An IED has five components: a switch (activator), an initiator (fuse), container (body), charge (explosive), and a power source (battery). An IED designed for use against armoured targets such as personnel carriers or tanks will be designed for armour penetration, by using a shaped charge that creates an explosively formed penetrator. IEDs are extremely diverse in design and may contain many types of initiators, detonators, penetrators, and explosive loads.

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