The Roman Catholic Church in Burundi accused the central African country's last active rebel group of "executing" Vatican ambassador Michael Courtney, whose fatal shooting has prompted international outrage.
"From the way he was executed, and I am speaking of a real execution, we can see that Monsignor Courtney had been looked for," Archbishop Ntamwana, the head of Burundi's episcopal conference, said in the capital Bujumbura.
Courtney, 58, an Irish archbishop, died in a Bujumbura hospital on Monday evening some three hours after being shot in the head, shoulder and arm during an ambush south of the capital which the army immediately blamed on the National Liberation Forces (FNL) rebel group.
The FNL denied the charge and blamed the army.
A funeral service was set for Wednesday in Bujumbura, before Courtney's body was flown back to Ireland for burial.
"We are now getting accounts from witnesses in the area. The nuncio's appeals to the FNL to stop fighting and their reactions show, in my opinion, that we need not look for the culprits outside the FNL," said Ntamwana.
The FNL is the only armed Hutu group still active in Burundi, where civil war has claimed more than 300,000 lives since 1993.
All similar groups have made peace with the government and joined its ranks, but the FNL refuses to recognise the administration's legitimacy.
Courtney had been instrumental in convincing these other groups to give up their armed struggle and had made numerous appeals to the FNL to follow suit.
"Since 1993, I have never seen the army chase someone in a car. It is not their strategy. The rebels' technique can really be seen here," said Ntamwana.
"In any case, the army had never been called into question by the nuncio, especially not lately. I cannot see the army doing such a thing," he added.
On Monday evening, Burundi President Domitien Ndayizeye, a Hutu, said that whoever carried out the ambush knew whom they were targeting, but did not name the FNL.
"Because the nuncio was in his usual car with all its distinctive markings, I am all but persuaded that the person who shot at him did it on purpose," he told reporters.
Courtney was the first papal nuncio to die a violent death in the recent history of the Holy See and his death prompted words of outrage and tribute from within Burundi and abroad.
His death was not in vain, said the head of the country's largest armed Hutu group, which made peace with the government in November and has now joined its ranks.
"Monsignor Courtney gave his life for this country. The blood that he spilt should serve as a lesson for all Burundians, so that they put a permanent end to the war," said the leader of the Forces for the Defence of Democracy (FDD), Pierre Nkurunziza, who is now a government minister.
"He was a brave man who was never afraid," said Bernard Budurira, a Burundian bishop with whom Courtney spent his last night after attending the funeral of a priest.
Courtney dismissed his colleague's pleas not to travel back to Bujumbura by road because of ongoing clashes, declaring with typical aplomb: "I'll put on all my bishop's vestments. That way, if someone shoots me they won't be able to lie and pretend they didn't know who I was."
Irish Prime Minister Bertie Ahern condemned the attack while Ireland's Cardinal Desmond Connell said he was greatly distressed.
Irish Foreign Minister Brian Cowen Tuesday praised his slain fellow-countryman as an exceptional diplomat who had worked tirelessly for peace and reconciliation.
"Archbishop Courtney was well known in the Department of Foreign Affairs as an exceptional diplomat who gave dedicated service to the Holy See in many difficult and challenging postings," he said in a statement from Dublin.
Burundi had "lost a close friend who dedicated himself to building a peaceful future for their country. The search for full and lasting peace must go on," the statement said.
The Irish government would use its presidency of the European Union over the coming six months "to ensure that the full weight of the EU is mobilised behind efforts to bring about a final end to violence in that country.
"That would be the best tribute that could be paid to the memory of Archbishop Michael Courtney," Cowen said.
The FNL late Tuesday reiterated that they were innocent of the crime.
"We wish to reaffirm our innocence in this affair and we call for an impartial enquiry," spokesman Pasteur Habimana told AFP.
He claimed Archbishop Ntamwana was angry with the FNL because it had refused to have him present at failed peace talks last month in Nairobi.