Michael Hayes told the Mail on Sunday that he "blew up Earl Mountbatten."

This is the first time that Hayes, who now lives in Dublin and previously apologized for his involvement in the fatal 1974 IRA bombings in Birmingham, has publicly claimed responsibility for the attack.

On August 27, 1979, a bomb was remotely detonated on a fishing vessel off the coast of Mullaghmore, Co Sligo. Lord Louis Mountbatten, his 14-year-old grandson Nicholas, the boy's 83-year-old grandmother Lady Doreen Brabourne, and 15-year-old crewman Paul Maxwell were all killed.

The IRA claimed responsibility for the attack and Thomas McMahon, who planted the bomb, was arrested at a Garda checkpoint in Co Longford. McMahon was jailed for life but was released after 19 years under the Good Friday Agreement. 

Speaking to a Mail on Sunday reporter, Hayes claimed that he was McMahon's "commanding officer."

Hayes said: "Tom McMahon, he was only a participant. I am an explosives expert, I am renowned. I was trained in Libya. I trained there as an explosives expert"

Asked if he was saying that he was the man who designed the bomb, Hayes said: "Yes, I blew him up.

"McMahon put it on his boat ... I planned everything, I am commander in chief."

Hayes confirmed to the Mail on Sunday that he was in Co Sligo at the time of the bombing.

"Francis McGirl [who was charged and acquitted for his involvement] made a b******s of it," Hayes said.

"I blew up Earl Mountbatten in Sligo, but I had a justification, he'd come to my country... Look at the Famine … are we to forget that? The Black and Tans? He came to my country and murdered my people and I fought back. I hit them back."

Hayes told the Mail on Sunday that he did not regret "blowing up Mountbatten."

He did, however, have regret about the two teens who were killed: "Them children were not supposed to be on the boat in the first place."

Hayes referred to the two teens as "casualties of war," but added: "Yes, I regret that, that wasn't meant to happen. I'm a father. I'm not made of stone. I was sickened, I cried."

DUP MP Ian Paisley Jr has called on gardai to investigate the "blood-curdling" claims made by Hayes.

"The sensational, shocking, and blood-curdling statement by a self-confessed, cold-blooded murderer ought to be immediately investigated by the police and the man brought to justice," he said.

Elsewhere, Mary Hornsey, the mother of 15-year-old Paul Maxwell, told the Belfast Telegraph that she would welcome an investigation into Hayes' claims, stating that she is seeking "justice, not revenge."

She added that the death of her son is "something that never goes away."

Hayes' claims about the attack on Mountbatten come six years after he issued an apology for his involvement in the 1974 IRA bombings in Birmingham that killed 21 people, though he would not say what role he played in the attack.

"I was a participant in the IRA's activities in Birmingham. How clear can I make it?" Hayes told BBC in 2017.

When asked if he planted the bombs, Hayes said: "I was a participant in the IRA's campaign in England."

He added: "I apologize not only for myself,  I apologize for all active republicans who had no intention of hurting anybody and sympathize with you [the victims and their families]."