It is believed to have been a reprisal Revenge for the Irish Republican Army 's ( IRA ) killing Killing of two policemen the day before .

Northern Ireland 's police forces – especially the USC , which was almost exclusively Protestant and unionist – were implicated Bodily_harm in a number of attacks Attack on Catholic and Irish nationalist civilians as reprisal Revenge for IRA actions .

A week later , six more Catholics were killed Killing in another reprisal attack Attack .

While approaching Arriving the eastern suburbs of the city , the Red Army temporarily halted Process_end combat operations , enabling Preventing_or_letting the Germans to regroup Cause_to_amalgamate and defeat Conquering the Polish resistance and to raze the city in reprisal .

an alliance of islamic jihad and the popular resistance Control committees claimed Statement responsibility for the attack Attack , stating Statement that it was carried out Action in reprisal for the assassinations of hamas leaders sheikh ahmad yassin and abdelaziz rantisi by the israeli army some weeks earlier .

Many media outlets also suspected Suspicion the insurgent group 's involvement in the attack Attack based on earlier reprisal warnings Warning it had issued Creating in the wake of Operation Linda Nchi from 2011 to 2012 .

The British government bolstered Cause_change_of_strength the RIC with recruits from Britain—the Black and Tans and Auxiliaries—who became Becoming notorious for ill-discipline and reprisal attacks Attack on civilians , some of which were authorised Preventing_or_letting by the British government .

They attacked Attack Catholics in reprisal for IRA actions , and in Belfast a sectarian conflict Hostile_encounter raged in which almost 500 were killed Killing , most of them Catholics .