The UN has said it is heartened by the response of the Lebanese authorities following the death of an Irish peacekeeping soldier amid reports arrests have been made.

Irish Defence Forces Private Sean Rooney, from Newtowncunningham, Co Donegal, was killed when his convoy came under attack while travelling to Beirut on December 14.

In a statement on Monday, the UN declined to comment on reports that at least one arrest has been made in Lebanon.

A spokesperson said there is an “ongoing investigation into this tragic incident, therefore we can’t pre-empt its results and we need to protect the outcome of the investigation”.

They added: “This incident was deeply shocking, a crime against Unifil peacekeepers who have travelled from far to work in preserving stability in a volatile environment and to work in support of the local population.

“We have asked to find out what happened, and for the perpetrators to be brought to justice.

“And we ask that people refrain from sharing harmful information, because disinformation is the fuel on which the fire of violence can spark.

“We need swift and effective investigations to find those responsible and hold them accountable for their crimes.

“We are heartened by the support of the Lebanese authorities and leaders from across the political spectrum, and we are hopeful that we can get to the truth.”

The Irish Defence Forces said: “There are three investigations currently ongoing into this incident.

“As these investigations are currently ongoing, the Defence Forces has no further comment to make at this time.”

The 24-year-old’s body was returned to his family after being repatriated from Lebanon last Monday, with his funeral taking place on Thursday in Dundalk.

Mourners at Holy Family Church, including Irish President Michael D Higgins, Irish premier Leo Varadkar, Tanaiste Micheal Martin and Garda Commissioner Drew Harris, as well as some of Pte Rooney’s colleagues from Lebanon, hear him described as a “national hero”.

In his homily, Fr Derek Ryan said Pte Rooney’s death “really did pierce the heart of his family” and the wider community.

“It breaks the human heart when a loved one dies serving their country for the important work of peacebuilding,” the parish priest told mourners. “It breaks all our hearts.”

Fr Ryan read a statement by Pte Rooney’s fiancee Holly who said as her relationship with Sean advanced “it became clear, Sean is not only my other half, he’s my better half”.

“I can say for certain that he would have been a fantastic husband and an even better father,” she said.

Pte Rooney was buried at All Saints Catholic Church in Colehill, Co Donegal, with full military honours which included the firing of a volley of 21 shots and the playing of the Last Post.

He was awarded a number of honours posthumously, including a peacekeeping medal from the UN and an appreciation medal from the Lebanese armed forces.

Another soldier who was injured in the same incident was flown back to Ireland on Wednesday to receive further medical treatment.

Private Shane Kearney, 22, from Killeagh, Co Cork, suffered a serious head injury. Two other peacekeepers were treated for minor injuries.

The soldiers were part of 121st Infantry Battalion, comprising 333 Irish troops, which was deployed in November to south Lebanon as part of the United Nations Interim Force in Lebanon.