as well as putting down riots and stopping Republican and Loyalist paramilitary groups from committing terrorist attacks. However, as the Provisional Irish Republican Army campaign grew in ferocity in the early 1970s, the Army was increasingly caught in a situation where its actions were directed against the IRA and the Catholic Irish nationalist community which harboured it. In the early period of the conflict, British troops mounted several major field operations. The first of these was the Falls Curfew of 1971, when over 3,000 troops imposed a 3-day curfew on the Falls Road area of Belfast and fought a sustained gun battle with local IRA men. In Operation Demetrius in June 1971, 300 paramilitary suspects were interned without trial, an action which provoked a major upsurge in violence. The largest single British operation of the period was Operation Motorman in 1972, when about 21,000 troops were used to restore state control over areas of Belfast and Derry, which were then controlled by republican paramilitaries. The British Army's reputation suffered further from an incident in Derry on 30 January 1972, Bloody Sunday in which 13 Catholic civilians were murdered by The Parachute Regiment. The biggest single loss of life for British troops in the conflict came at Narrow Water, where eighteen British soldiers were killed in a PIRA bomb attack on 27 August 1979, on the same day Lord Mountbatten of Burma was assassinated by the PIRA in a separate attack. In all almost 500 British troops died in Northern Ireland between 1969 and 1997. By the late 1970s, the British Army was replaced to some degree as "frontline" security service, in preference for the local Royal Ulster Constabulary and the Ulster Defence Regiment (raised 1970) as part of the Ulsterisation policy. By the 1980s and early 1990s, British Army casualties in the conflict had dropped. Moreover, British Special Forces had some successes against the PIRA – see Operation Flavius and the Loughgall Ambush. Nevertheless, the conflict tied up over 12,000 British troops on a continuous basis until the late 1990s and was ended with the Good Friday Agreement which detailed a path to a political solution to the conflict. Operation Banner came to an end in 2007 making it the longest continuous operation in the British Army's history, lasting over thirty-eight years. Troop numbers were reduced to 5,000. England In 1980, the Special Air Service emerged from its secretive world