Original sentence: The Omagh bombing was a paramilitary car bomb attack carried out by the Real Irish Republican Army (RIRA), a splinter group of former Provisional Irish Republican Army members opposed to the Belfast Agreement, on Saturday 15 August 1998, in Omagh, County Tyrone, Northern Ireland
Edited sentence: The Omagh bombing was a car bomb attack carried out by the terrorist organisation  , the Real Irish Republican Army (RIRA), a splinter group of former Provisional Irish Republican Army members opposed to the Belfast Agreement, on Saturday 15 August 1998, in Omagh, County Tyrone, Northern Ireland