The United Nations today accused the Sudanese government of being directly involved in the mass-rape of girls and women in the crisis-hit region of Darfur — a damning indictment of the part played by the country's Islamist dictatorship in the humanitarian catastrophe.

A report by the UN high commissioner for human rights says it has evidence that the Sudanese Army was involved alongside Arab militia in looting at least three towns, raping girls and women and killing at least 115 people.

The attacks on Sirba, Sileia and Abu Suruj on February 8 by helicopter gunships and aircraft caused 30,000 to flee their homes, Louise Arbour, the UN high commissioner for human rights, said in her report.

The study is the latest authoritative UN report, based on eye-witness testimonies and evidence from aid workers, suggesting that President Omar al-Bashir's administration is providing help and support to the brutal Arab janjaweed militia, who have reportedly robbed villages and murdered, raped or displaced their residents.

Last year, a UN report produced photographic evidence that the Sudanese government was carrying out secret bombing raids by disguising its jets as United Nations aid planes. Sudan denies the claims.

The UN says that the crisis afflicting the wartorn Darfur region has so far killed up to 400,000 people, and displaced a further 2.3 million, and campaigners have called on governments worldwide to isolate Mr al-Bashir's regime for its involvement.

“The scale of destruction suggests that the damage was a deliberate and integral part of a military strategy,” the nine-page report on the rapes said.

It added that its concerns were ignored in discussions with the Sudanese-appointed governor of West Darfur. Other government officials denied collusion between the army and militias.

Most of Abu Suruj and much of Sileia was burnt down when militia on camels and horses joined the Sudanese army in attacking the towns, the report said. Some residents were burnt alive inside their homes, including a 75-year-old blind woman and a disabled girl, the report said.

Ms Arbour’s report added that there were also “strong indications" that members of the Sudanese Armed Forces, or SAF, committed rapes of women and girls in Sirba, located 30 miles north of West Darfur’s capital, El Geneina. “One eyewitness reported that she witnessed four girls being escorted to an abandoned hut and raped at gunpoint by a group of soldiers belonging to the SAF,” the report said.

It said armed men on camels and horses shot indiscriminately at Sirba’s residents and systematically torched and looted homes. Government troops did nothing to stop the atrocities, the report added.

In Sileia and Abu Suruj, eyewitnesses told UN investigators that Sudanese Armed Forces also took part in the pillaging.

“I witnessed SAF and janjaweed looting houses, shops and NGO offices,” an eyewitness was quoted as saying. “They would load the stolen goods in their cars and on their camels and horses and take them away.”

Human rights groups have long claimed that the oil-rich Sudanese government should be internationally isolated to punish it for its role in the crisis. However China, its biggest international investor, has refused to do so, despite threats of sanctions led by Britain and the United States.

The issue has led to Steven Spielberg’s withdrawal as an artistic adviser for this summer's Olympic Games, a decision which was heavily criticised by China.

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