ARUSHA, Tanzania: The UN-backed tribunal for Rwanda on Monday upheld the life sentences for two former heads of the ex-ruling party for genocide crimes committed in 1994.

Matthieu Ngirumpatse and Edouard Karemera, the former chairman and deputy of Rwanda’s then-ruling National Revolutionary Movement for Development, had been handed life terms in 2011.

They were convicted of genocide, crimes against humanity and for not having prevented or denounced crimes committed by the party’s infamous youth militia, the Interahamwe, but had appealed the verdicts.

An estimated 800,000 people, mostly minority Tutsis, were killed in the genocide in just 100 days — a rate of killing that was far faster than the Holocaust of the Jews in Second World War.

“The Appeals Chamber, seated in open session, affirms the sentence of life imprisonment imposed by the trial chamber,” Appeals Judge Theodor Meron said in his ruling.

He added the two would remain in detention pending their transfer to a jail in another country where they will serve their sentence. Rwandan authorities welcomed the verdict.

“There is a feeling of satisfaction to see that justice has been done,” said Alain Mukuralinda, spokesman for Rwanda’s prosecutor general.

“One thing is important, that the court has upheld that when you hold a position of authority and that crimes are committed under that authority, you are responsible even if you didn’t directly give orders,” he added.

Ngirumpatse was arrested in Mali in June 1998 and transferred to Arusha the following month. Karemera was arrested the same year in Togo.

The International Criminal Tribunal for Rwanda (ICTR) was set up to try those alleged to bear the greatest responsibility for the 1994 genocide, and Monday’s cases was among the final procedures the body has had to handle before its scheduled closure later this year.

Lesser suspects have been judged by the Rwandan courts and by several thousand grassroots courts, known as ‘gacaca’, that were set up by the Rwandan government to deal with the sheer number of cases.

According to the ICTR, Ngirumpatse, born in 1939, and Karemera, born in 1951, were both key architects of the genocide, and formed a “joint criminal enterprise seeking to destroy the Tutsi ethnic group”.

Starting with the delivery of weapons to the Interahamwe militia at Kigali’s Diplomates hotel in the hours before the massacres began, they went on to rally support from “figures from the interim government, political leaders, Interahamwe chiefs and influential businessmen”.

Their actions resulted in widespread killings as well as “rapes and the sexual crimes carried out on Tutsi girls and women by soldiers and militia”, according to the initial judgement.

The two were active until mid-July 1994, when Hutu extremists were pushed out by the Rwandan Patriotic Front (RPF), the Tutsi rebels led by Paul Kagame, who is now Rwanda’s president.

The ICTR is still dealing with seven more appeals, while nine suspects sought by the ICTR are still fugitives.