Mourners watch as the coffin of slain journalist Lyra McKee is taken out of the church after her funeral at St. Anne’s Cathedral in Belfast. (Charles McQuillan/Pool/Reuters)

The funeral to celebrate the life of journalist Lyra McKee, who was shot dead by dissident republicans while covering a police raid and riot last week, brought together bitter political rivals.

There was British Prime Minister Theresa May and opposition Labour Party leader Jeremy Corbyn.

The head of the Democratic Unionist Party, Arlene Foster, was there, too. She sat beside the leaders of Sinn Fein, Michelle O’Neill and Mary Lou McDonald — though the two parties are so antagonistic that they have refused to serve together in Northern Ireland’s parliament for the past two years.

The priest, Martin Magill, told the mourners, “I commend our political leaders for standing together in Creggan on Good Friday,” the day after the shooting. “I am, however, left with a question: Why in God’s name does it take the death of a 29-year-old woman, with her whole life in front of her, to get us to this point?”

The cathedral erupted in a standing ovation.

McKee was near a police van in Creggan, an Irish Catholic neighborhood in the Northern Irish city of Londonderry, also known as Derry, on the night of April 18 when a masked gunman fired at officers and others. A bullet struck the young journalist in the head.

In a communique to the Irish News, using a recognized code word, the paramilitary group “New IRA” said one of its cadre was responsible for her death and offered “sincere apologies.”

“In the course of attacking the enemy Lyra McKee was tragically killed while standing beside enemy forces,” the group said, reviving both the fear and revulsion that the days of sectarian violence could return to Northern Ireland. 

On Wednesday, St. Anne’s Cathedral was filled. Although the house of worship is Church of Ireland, the service was ecumenical, officiated by a Protestant dean and the Catholic priest Magill. McKee’s family said she would have wanted it that way.

“There is a younger generation coming up in the town and they don’t need guns put in their hands,” Magill continued. “They need jobs, they need a better health service and education. They need a life.”

Before the service, the overflow crowd outside began to clap with the arrival of the coffin, which featured Celtic etchings and was bedecked with wreaths that spelled out the words “Team Lyra” in the rainbow colors of the LGBT community, of which the young writer and activist was a prominent member.

Some of McKee’s friends attended the service dressed in Harry Potter-themed jackets and Hogwarts scarves. The journalist was a big fan of J.K. Rowling’s work.

Two young women performed the song “Dreams” by the Cranberries. It has been popular again, featured on the British hit TV sitcom “Derry Girls,” set in Northern Ireland in the 1990s during “the Troubles,” the 30 years of vicious sectarian strife that left 3,500 dead.

Patrick Kielty, a comedian from Northern Ireland whose father was killed by the loyalist paramilitaries with the Ulster Defense Association, wrote on Twitter: “Today Lyra McKee is laid to rest. She believed in peace, tolerance and equality. The exact opposite of those responsible. They will never win because Lyra will always be the future. And her truth will continue to be told.” 

Speaking at the beginning of the service, the dean of St. Anne’s, the Very Rev. Stephen Forde, said: “Lyra was a person who broke down barriers and reached across boundaries, this was her hallmark in life, this is her legacy in death.”

He added: “She was a child of the Good Friday Agreement,” the 1998 accord that mostly ended the violence in Northern Ireland. “She was a primary school pupil in north Belfast when the agreement was signed. She grew up to champion its hope for a society that was free from the prejudices of the past.”

House Speaker Nancy Pelosi (D-Calif.) last week led a congressional delegation to London, Belfast and Londonderry, where she repeatedly warned all sides that if the chaos of Brexit did anything to undermine the Good Friday Agreement — by imposing again, for example, a hard border between Northern Ireland and the Republic of Ireland, then Congress would block any trade deals between the United States and Britain.

In reaction to McKee’s killing, friends of the journalist on Easter Sunday went to the Londonderry headquarters of the dissident republicans and dabbed their handprints, covered with red paint to symbolize blood, over the building’s facade. 

Irish Prime Minister Leo Varadkar and British Prime Minister Theresa May wait as the coffin of slain journalist Lyra McKee is taken out of the church after the funeral. (Charles McQuillan/Pool/Reuters)

Nearby, in the area of the city known as the “Free Derry Corner,” the scene of violent clashes between British forces and Irish republicans in the past, someone had spray-painted graffiti proclaiming: “Not in Our Name. RIP Lyra.”

Alongside some older graffiti that read “IRA,” someone else had added the words, “Are Done.”

The Derry group associated with the “New IRA,” called Saoradh, had its social media accounts on Facebook and Twitter suspended.

Members of the original Irish Republican Army, or IRA, put down their weapons in the cease-fire that accompanied the peace accord more than 20 years ago. The “New IRA” represents a very small number of dissident republicans who consider Northern Ireland, a part of the United Kingdom, as “occupied territory” and the Police Service of Northern Ireland as an illegitimate force. They reject the peace accord and continue to press — politically, but also with guns and bombs — for a unified Ireland.

In the House of Commons on Tuesday evening, Northern Ireland Secretary Karen Bradley said, “To those responsible for this act of terrorism, we say we have heard your excuses and your hollow apologies. No one buys it.”

McKee’s mother, sisters, brothers and her partner, Sara Canning, issued a statement before the funeral acknowledging “the outpouring of support and love we have witnessed this past few days.”

“We as a family know that the whole community has been touched by the events of Thursday night and that many are rightly angry,” they said. “Lyra’s answer would have been simple, the only way to overcome hatred and intolerance is with love, understanding and kindness.”

Members of the National Union of Journalists, of which McKee was a member, escorted her coffin down the steps of the cathedral after the funeral.

Police on Wednesday continued their investigation into the killing, which they have labeled a terrorist act. Several people have been arrested and released.

Booth reported from London.