A DUP MP has said it is "incredible that someone would expect praise for saying sorry for the murder of two adults and two children" after the leader of Sinn Fein apologised for the IRA's killing of Lord Mountbatten in Sligo in 1979.
Mary Lou McDonald was speaking following the funeral of Prince Philip, Lord Mountbatten's nephew on Saturday.
She told Times Radio she was sorry that Mountbatten (79) was killed when the fishing boat he was on was blown up by the IRA.
The Sinn Fein leader was asked whether she would be willing to apologise to Prince Charles, who had a particularly close relationship with Mountbatten.
"The army and armed forces associated with Prince Charles carried out many, many violent actions on our island," Mrs McDonald said.
"I can say of course I am sorry that happened. Of course, that is heartbreaking. My job, and I think that Prince Charles and others would absolutely appreciate this, my job is to lead from the front, now, in these times."
The Sinn Fein leader said she wanted to ensure no other family lost a loved one to conflict.
"I believe it is all our jobs to ensure that no other child, no other family, no matter who they are, suffers the same trauma and heartbreak that was all too common on all sides of this island and beyond," she said.
"I have an absolute responsibility to make sure that no family faces that again and I am happy to reiterate that on the weekend that your Queen buried her beloved husband."
Apology: Mary Lou McDonald has said sorry for the 1979 murder of Lord Mountbatten
However, East Londonderry DUP MP Gregory Campbell said: "We note the apology relating to the 1979 murders in Mullaghmore. It is incredible that someone would expect praise for saying sorry for the murder of two adults and two children.
"At the time Gerry Adam's said, 'I don't think he could have objected to dying in what was clearly a war situation. He knew the danger involved in coming to this country. In my opinion, the IRA achieved its objective."
"Adams stood by this in a 2017 interview. Has the Sinn Fein position now changed?
"An apology is one thing, we now need to see condemnation and justice for all the murders that took place that day."
Lord Mountbatten was holidaying at Classiebawn Castle, Mullaghmore on August 27, 1979 when he was murdered by the IRA. A bomb exploded on the Shadow V boat he was fishing on, and while he was pulled alive from the water by nearby fishermen, he died from his injuries before being brought to shore.
Also killed were Lady Doreen Brabourne, the 83-year-old mother-in-law of Mountbatten's daughter; his grandson Nicholas Knatchbull (14); and Fermanagh schoolboy Paul Maxwell, who was working as a boat boy while on holiday with his parents.
That same day at Warrenpoint, Co Down, 18 soldiers were murdered in an IRA attack.
Mrs McDonald's predecessor, Gerry Adams, had previously declined to apologise for Mountbatten's death.