The body of Irish UN peacekeeper Seán Rooney is to be flown home from Lebanon on an Air Corps plane this afternoon.

In a statement, the Defence Forces said that there will be a solemn UN ceremony to honour Private Rooney in Beirut Airport before departure.

His remains will be brought to Casement Aerodrome in Baldonnel and reunited with his family tomorrow morning.

The 24-year-old was killed in an attack on Wednesday while serving as part of the UN peacekeeping mission in the country.

A large contingent of Irish soldiers, part of the 121st UN battalion, are at the airport for the ceremony.

His colleague Trooper Shane Kearney, 23, was seriously injured.

Minister for Enterprise Simon Coveney said the news is "more optimistic" about the condition of Trooper Kearney.

Speaking on RTÉ's The Week in Politics, Mr Coveney said he is breathing independently and his head injuries are being managed.

"He is doing well given circumstances and seriousness of his injuries," the minister said.

"We're also putting plans in place to bring him home and to make sure that he can continue to get the necessary specialist supports that he needs here at home as soon as it's safe to travel with him."

A team of eight Defence Forces personnel travelled to Lebanon yesterday to support members of the battalion of Pte Rooney.

Members of the team are also assisting the United Nations Interim Force in Lebanon (UNIFIL) in an investigation into what happened.

Yesterday, the Defence Forces said that two soldiers who were part of the convoy on Wednesday and received minor injuries had been discharged from hospital.

Three investigations are being conducted into Wednesday's attack.

Investigators from UNIFIL, the Lebanese authorities led by a military prosecutor, and the Irish Defence Forces will separately try to figure out precisely what happened.

Mr Coveney, who was Minister for Foreign Affairs and Defence until yesterday's Cabinet reshuffle, said they "will get to the bottom of what happened" in Lebanon.

The minister said he has spent time with Pte Rooney's family this week, describing them as "incredibly strong, impressive people".

He said he has spoken with the Lebanese foreign and defence ministers "in very blunt terms" about their expectations for a full cooperation in relation to all aspects of the investigation.

"We will get to the bottom of what happened here and the truth, we owe that to all of our Defence Forces personnel and in particular to Seán Rooney's family," he said.

"We hope to ensure that we will be able to repatriate Seán within next 24 hours and I think it's certain now that his body will leave Lebanon today and arrive back home tomorrow."

Minister Coveney said he does not accept Hezbollah's statement that this was "an unintentional accident".

He said Hezbollah "controls a lot of people and a lot of weapons" in that region and is "part of the problem".

Independent TD and former Defence Forces member Cathal Berry said that what happened in Lebanon was "murder, plain and simple".

Speaking on the same programme, Mr Berry said it is "very important" that the perpetrators are brought to justice.

He said it is important that the mission remains and UNIFIL "is actually doing its job".

"It is containing the conflict, it is maintaining stability and it is providing the space for a political solution, if a political solution is actually achievable," he said.