A former army colonel was jailed for life yesterday after being found guilty of masterminding the 1994 Rwandan genocide in which more than 800,000 people were slaughtered in 100 days — history’s fastest mass killing.

A special UN tribunal found that Theoneste Bagosora, 67, and two co-defendants had plotted and organised the killings of ethnic Tutsis and moderate Hutus opposed to the rule of President Habyarimana.

It is the first time that the International Criminal Tribunal for Rwanda (ICTR), based in the northern Tanzanian town of Arusha, has convicted anyone for organising the killings. Two other former military officers, Anatole Nsengiyumva and Aloys Ntabakuze, were also found guilty of genocide, crimes against humanity and war crimes. All three were given life sentences.

The three organised, armed and trained the notorious Interahamwe militia, which carried out much of the slaughter. Most of the killings took place with machetes and thick wooden sticks covered with nails.

The court found Bagosora guilty of chairing a committee that drew up lists of those to be massacred, rejecting his defence that the killings were not organised and therefore not genocide. It ruled that he planned the murders as early as 1990 and had drafted a paper circulated within the army describing Tutsis as “the principal enemy”.

He later stormed out of peace talks, accusing government delegates of being too soft on Tutsi-led rebels and said that he was returning to Kigali to “prepare the apocalypse”.

Bagosora’s lawyer said that his client would appeal against the verdict. A fourth man, Brigadier Gratien Kabiligi, the former head of military operations, was cleared and ordered to be released from custody immediately.

Rwanda, which has had a fraught relationship with the UN court, immediately welcomed the verdict. “Justice has been delivered. We are satisfied,” Aloys Mutabingwa, the Rwandan representative to the ICTR, declared. “The essential thing is that their role in the genocide was established. The court ruled that Bagosora had the authority over the killers. It is the most important thing.”

The killings began a few hours after the aircraft of President Habyarimana, a Hutu, was blown up on its approach to Kigali airport as he returned from failed peace talks on April 6, 1994.

The court found that among the first to be targeted by Bagosora were the Prime Minister, Agathe Uwilingiyimana, a moderate Hutu in favour of a government of national unity with Tutsi rebels, and her bodyguard of ten Belgian UN peacekeepers.

The peacekeepers’ bodies were horribly mutilated — an act that outraged public opinion in Belgium and led the Government to withdraw its contingent to the UN force and abandon more than 2,000 Tutsi civilians who had sought refuge at their base at the École Technique in Kigali.

They were all slaughtered within an hour of the pullout, an event later recorded in several films about the genocide.

The UN force commander, General Roméo Dallaire, who begged the Belgians to stay, described Bagosora as the “kingpin” behind the genocide. In his memoir, Shake Hands with the Devil, the Canadian officer wrote that Bagosora was a “known extremist” who controlled the militia leaders as much as anyone could.

At their last meeting on Rwandan soil, Bagosora said that the next time he saw the general he would kill him. Their subsequent encounter was in the Arusha courtroom when Mr Dallaire, who suffered a breakdown after the genocide, testified for the prosecution.

When The Times met Bagosora, then a colonel, on Day 10 of the genocide, he claimed to be deploying the Rwandan Army to stop the killings, despite being surrounded by a smiling group of drunk militia leaders, many of whom wore bloodstained clothes.

He angrily denounced efforts by the International Committee of the Red Cross to escort Tutsi children to safety while his supporters menacingly drew fingers across their throats.

It was later alleged that France, which supplied the Habyarimana Government with arms and finance even as the genocide had begun, took Bagosora to safety by helicopter after Tutsi rebels advanced across the country, captured the capital and ended the killings.

In 1996 Bagosora was captured in Cameroon and flown to Arusha to stand trial.

The case, which began in 2002 and was expected to last two years, became the lengthiest and most complex the ICTR had yet handled.

About 242 witnesses, many of them survivors flown from Rwanda, were called, more than 1,600 exhibits displayed and about 30,000 pages of transcripts compiled.

In another verdict yesterday, the UN tribunal for Rwanda — which has only one year left to run — also sentenced Habyarimana’s brother-in-law, Protais Zigiranyirazo, a businessman known as “Monsieur Z”, to 20 years in prison for genocide and extermination as a crime against humanity.

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