 Both the Provisional and Official IRA stepped up attacks after Bloody Sunday , with the tacit support of the residents . Local feelings changed , however , with the killing of Ranger William Best by the Official IRA . Best was a 19 @-@ year @-@ old local man who was home on leave from the British Army at his parents ' house in the Creggan . He was abducted , interrogated and shot . The following day 500 women marched to the Republican Club offices in protest . Nine days later , on 29 May , the Official IRA declared a ceasefire . The Provisional IRA initially stated that they would not follow suit , but after informal approaches to the British Government they announced a ceasefire from 26 June . Martin McGuinness was the Derry representative in a party of senior Provisionals who travelled to London for talks with William Whitelaw , the Secretary of State for Northern Ireland . The talks were not resumed after the ending of the truce following a violent confrontation in Belfast when troops prevented Catholic families from taking over houses in the Lenadoon estate . 
 Both the Provisional and Official IRA stepped up attacks after Bloody Sunday , with the tacit support of the residents . Local feelings changed , however , with the killing of Ranger William Best by the Official IRA . Best was a 19 @-@ year @-@ old local man <a href='null_relcl' title='1'><mark>who</mark></a>was home on leave from the British Army at his parents <a href='null_genetive' title='2'><mark>'</mark></a>house in the Creggan . He was abducted , interrogated and shot . The following day 500 women<a href='been_done' title='3'><mark></mark></a> marched to the Republican Club offices in protest . Nine days later , on 29 May , the Official IRA declared a ceasefire . The Provisional IRA initially stated that they would not follow <a href='negative_concord' title='4'><mark>suit</mark></a> , but after informal approaches to the British Government they announced a ceasefire from 26 June . Martin McGuinness was the Derry representative in a party of senior Provisionals <a href='null_relcl' title='5'><mark>who</mark></a><a href='uninflect' title='6'><mark>travelled</mark></a> to London for talks with William Whitelaw , the Secretary of State for Northern Ireland . The talks <a href='uninflect' title='7'><mark>were</mark></a> not resumed after <a href='None' title='8'><mark>the</mark></a><a href='negative_concord' title='9'><mark>ending</mark></a> of the truce following a violent confrontation in Belfast when troops prevented Catholic families from taking over houses in the Lenadoon estate . 
Both the Provisional and Official IRA stepped up attacks after Bloody Sunday , with the tacit support of da residents . Local feelins changed , however , wid the killing of Ranger William Best by tdaOfficial IRA . Best was a 19 @-@ year @-@ old local man was home on leave from the British Army at his parents  house in the Creggan . He was abducted , interrogated and shot . The following day 500 women been marched to the Republican Club offices in protest . Nine days later , on 29 May , the Official IRA declared a ceasefire . The Provisional IRA initially stated dat they would not follow no suit , but after informal approaches to the British Government they announced a ceasefire from 26 June . Martin McGuinness was thdaerry representative in a party of senior Provisionals traveled to London fa talks with William Whitelaw , the Secretary of State for Northern Ireland . Thedalks was not resumed after no ending of the truce following a violent confrontation in Belfast when troops prevented Catholic families from takin ova houses in the Lenadoon estate .