DUBLIN (Reuters) - The IRA bomber who blew up Lord Mountbatten, Queen Elizabeth‘s cousin, has been released from an Irish prison as part of Northern Ireland‘s peace process, the justice department said on Friday. Thomas McMahon, 50, was jailed for life of preparing the 23 kg bomb that killed Mountbatten, Britain‘s last colonial viceroy of India, and three other people in August 1979. The bomb blew their boat out of the water in Donegal bay off Ireland‘s northwest coast, where Mountbatten had a holiday home. McMahon has since dissociated himself from the Irish Republican Army (IRA), which has fought with bombs and bullets for an end to British rule. He had been on a day release programme at Dublin‘s Mountjoy jail since 1996. McMahon‘s release had been recommended by a commission set up under terms of the landmark Good Friday peace agreement signed in April aimed at ending decades of violence over the status of Northern Ireland. He was the seventh prisoner freed in Ireland this month under the terms of the agreement, which allowed for the release within two years of members of guerrilla groups that observe ceasefires. Supporters of the peace process argue it is right to free those responsible for 30 years of strife, in which more than 3,600 people were killed, if the groups they fought for are on a ceasefire, as the IRA has been since July last year. A pro-British politician in Belfast who is a prominent opponent of the peace deal said the release was premature because armed groups had not yet started handing in their weapons — the process of „decommissioning“ that is also set out in the peace deal. A string of bombings since the peace deal was signed has been blamed on an array of dissident republican groups who oppose the IRA‘s ceasefire and the peace accord for its failure to bring about Irish unity. Police suspect IRA involvement in the fatal shooting of Andrew Kearney, 33, in Belfast last month. Peter Robinson, deputy leader of the Democratic Unionist Party led by firebrand anti-agreement preacher Ian Paisley, said there was „no rhyme or reason“ for the prisoner releases. Britain‘s Conservative Party, whose former leader M. Thatcher escaped injury in an IRA bombing that killed five party members at a conference in Brighton in 1984, accused the Dublin government of acting too fast because decommissioning had not begun.