Blast bomb is a term used in Northern Ireland for a type of improvised explosive device. More specifically, these devices are usually a form of homemade grenade, which is thrown at a target. These devices have been used in a number of public order situations, and in attacks on the Royal Ulster Constabulary, its successor Police Service of Northern Ireland (PSNI) and British Army. A police officer was killed by a blast bomb in Northern Ireland during The Troubles by loyalists and in 2001 Loyalist protesters threw a blast bomb at Catholic schoolgirls, some as young as 4 years old, making their way to school in September 2001. Ordinary fireworks are sometimes used in a similar fashion to blast bombs. Such devices which are packed with nails are referred to as nail bombs.