In early February 1991 , another proxy bomb wrecked an Ulster Defence Regiment base in Magherafelt , County Londonderry , but there were no fatalities . The proxy bomb tactic caused outrage in both the unionist and nationalist communities . The final IRA use of proxy bombs came on 24 April 1993 , when they forced two London taxi drivers to drive bombs towards Downing Street and New Scotland Yard . There were no casualties , however , as the drivers managed to shout warnings and to abandon their cars in time . A conventionally-delivered bomb was detonated by the IRA on the same day in the financial centre of Bishopsgate , in Central London
detonated by the IRA
1993 Bishopsgate bombing
Proxy bomb