AS ceremonies end marking the 10th anniversary of Rwanda’s genocide, the United Nations, aid agencies and human rights organisations warn that another deliberate but slow-burning genocide is under way in Sudan.

Just as the former government in Rwanda gave weapons to Hutu militias to massacre the Tutsi, so Sudan’s government in Khartoum has armed an Arab militia to kill, rape and pillage non-Arabic speaking black Africans in western Sudan.

UN Secretary-General Kofi Annan warned last week that an international force may be needed to prevent Rwanda-style genocide in Sudan’s arid Darfur region. The area is about the size of Britain and home to a host of ethnic groups, including the Fur – Darfur translates as “Homeland of the Fur” – Massalit, Bargu, Zaghawa and Tunjur peoples. “The risk of genocide remains frighteningly real,” said Annan.

Human Rights Watch (HRW) last week said the Khartoum government had established a 20,000-strong Arab militia, called the Janjaweed or “Men on Horseback”, which is implementing “a strategy of ethnic-based murder, rape and forcible displacement of civilians”. At least 900,000 Furs and other black peoples have been forced from their Darfur homes, with about 110,000 fleeing as refugees to neighbouring Chad. The dead, says the New York and London-based HRW, number tens of thousands, though nobody knows for certain how many.

The horse and camel-mounted Janjaweed, equipped with automatic rifles and satellite phones, frequently attack after bombing raids on Darfur villages and towns by government MiG and Antonov aircraft.

“Hundreds and hundreds of villages have been destroyed, usually burned, with all property looted,” says HRW in a report titled Darfur In Flames: Atrocities In Western Sudan. “Key village assets have been destroyed in an apparent effort to render the villages uninhabitable.”

Kofi Annan’s UN humanitarian aid co-ordinator in the region, Mukesh Kapila, says: “This is more than just a conflict. It is an organised attempt [by Khartoum] to do away with a group of people. The only difference between Rwanda and Darfur now is the numbers of dead, murdered, tortured and raped involved.”

Kapila cites a Janjaweed operation of an assault on the Tawilah area of northern Darfur. He says 30 villages were burned to the ground, more than 200 people killed and more than 200 African girls and women raped . A UN report says some of the girls were raped by up to 14 assailants in front of their fathers who were then executed. A further 150 women and 200 children were abducted in the raid.

As refugees flee across the border of Africa’s biggest country, aid agencies report 1000 people a week are dying from hunger and disease in the refugee camps in Chad.

One of the few foreign correspondents to have reached the remote and harsh 850-mile Sudan-Chad border, the New York Times’s Nicholas Kristof, described the campaign by the Khartoum government and the Janjaweed as: “The most vicious ethnic cleansing you’ve never heard of – Western and African countries need to intervene urgently.

“Sudan’s leaders should not be able to get away with mass murder just because they are shrewd enough to choose victims who inhabit a poor region without airports, electricity or paved roads.”

The latest of a number of ceasefires between Khartoum and two Darfur rebel movements – the Sudan Liberation Army (SLA) and Justice and Equality Movement (JEM) – comes into effect today. It is scheduled to last 45 days to allow humanitarian agencies to reach the people affected by the fighting. Darfur has been a virtual no-go region for relief agencies because of a ban imposed on their movements by the Sudan government.

Theoretically, the 45-day truce will be automatically renewed next month unless any of the parties raise objections. But aid workers struggling to help the refugees in Chad and a handful of Darfur centres doubt whether the ceasefire will hold or help them much. “It’ll be the third or fourth cease-fire they’ve signed,” says Simon Salimini, who co-ordinates food distribution in five World Food Programme refugee camps in eastern Chad. “They come, they talk, they agree a cease-fire, and it lasts just a few months.”

Other aid workers doubt whether Khartoum can now control the Janjaweed militias, even it really wanted to. “The government gave the Janjaweed carte blanche to murder and rape at will,” says another aid worker in the Darfur town of Kutum to which tens of thousands of people have fled as surrounding villages are destroyed. “Will they be willing to voluntarily hand their weapons over when you are dealing with such a vast area?”

Fatma, an African villager who has moved with her infant children into Kutum, says: “Young girls can’t leave the camp to gather firewood. We are scared to send them out. They rape them. We can’t send the young men out because they will kill the men.”

Darfur contains a central fertile belt in the Jebel Marra mountains and was an independent sultanate until 1917, when it was incorporated into British-Egyptian Sudan. The sophisticated Arabs along the Nile in Sudan have always regarded the Darfur tribes as primitive. They are widely referred to as “Zurug” – roughly “niggers” – and have been subjected to a prolonged “Sudanisation” strategy.

In 1987 some 27 Arab nomad groups united in an attempt to drive the blacks from Darfur. The response of the Fur and other black tribes was to form their own militias. Early this year Sudan’s president, Omer Hassan Ahmed El Bashir, vowed to annihilate the rebels, who deeply worry Khartoum because, unlike the black rebels in the south, they are fellow Muslims and cannot be condemned as “infidels”.

The Darfur crisis is an especially tough personal problem for Kofi Annan, a black African himself, who recently admitted he was partly to blame, as then UN peacekeeping chief, for failing to prevent the Rwandan genocide.

A debate is now raging as to whether the events in Darfur should be described as “genocide” or “ethnic cleansing”. But last week the UN secretary-general said the reports he was receiving from Darfur left him with a deep sense of foreboding, before adding: “Whatever terms it uses to describe the situation, the international community cannot stand idle.”

11 April 2004