(CNN) The funeral of murdered journalist Lyra McKee on Wednesday drew leaders from across British and Irish politics, in a church service aimed at healing divisions.
British Prime Minister Theresa May, UK opposition Labour leader Jeremy Corbyn and Irish Taoiseach (or prime minister) Leo Varadkar attended the service at St. Anne's Cathedral in Belfast. St. Anne's is a Protestant church that welcomes Catholic clergy, chosen by McKee's Catholic family in a show of unity for a country shaken by religious violence.
McKee, 29, was shot by the New IRA while reporting on rioting last Thursday in the Northern Ireland city of Londonderry.
The city -- which is referred to by Irish nationalists as Derry and British unionists as Londonderry -- is a short drive from the border with the Republic of Ireland.
The New IRA, a dissident republican group, admitted responsibility in a statement to The Irish News. The group offered its "full and sincere apologies to the partner, family and friends of Lyra McKee for her death."
McKee, a prominent freelance journalist who wrote for publications including The Atlantic and Buzzfeed News, also campaigned for greater LGBT rights.
"Lyra was a person who broke down barriers and reached across boundaries," said Dean Stephen Forde in his opening comments to mourners.
"This was her hallmark in life, this is her legacy in death."
He said that McKee "was a child of the Good Friday Agreement," referring to the peace process in 1998.
Forde said McKee "grew up to champion its hope for a society that was free from the prejudices of the past."
Speaking at the service, McKee's sister Nichola Corner added that the journalist's legacy should be "a society where labels are meaningless."
Despite their differing political views, Northern Ireland's First Minister Arlene Foster sat alongside and chatted with Sinn Féin President Mary Lou McDonald during the service.
McKee's death is a stark reminder of the simmering tensions that remain in Northern Ireland, years after the Good Friday Agreement of 1998 brought an end to the "Troubles" -- the decades-long sectarian conflict in which more than 3,500 people died.
Addressing mourners, Father Martin Magill called on those who "had any part in her murder" to reflect on the journalist as "a powerful example of 'the pen is mightier than the sword.'"
"I plead with you to take the road of nonviolence to achieve your political ends," he added.
McKee's partner, Sara Canning, in a Facebook post earlier said the service would be a "celebration of her life."
Canning said she knew the Harry Potter fan "would love it" if people "would like to wear Hufflepuff, Harry Potter or Marvel related T-shirts" to the ceremony.
During the service, McKee's friend Stephen Lusty said the journalist had been planning on proposing to Canning. He added that he was "under strict instructions to wear my kilt" to the wedding and even "adorn it with some Harry Potter."