A year later , on 20 July 1982 , two bombs killed 11 British soldiers and injured 50 soldiers and civilians during the Hyde Park and Regent 's Park bombings . This was the deadliest IRA attack against the British Army in England during The Troubles . In December 1983 six people were killed and 90 injured in London when an IRA car bomb exploded outside Harrods . The IRA 's most notable attack in Britain on that period occurred in Brighton in October 1984 when they killed five people and injured dozens during the Brighton hotel bombing which was an attempt to kill British Prime Minister Margaret Thatcher
exploded outside Harrods
Harrods bombing
Chelsea Barracks bombing