(adds details throughout) By Stephanie Nebehay GENEVA, May 18 (Reuters) - The United Nations human rights office on Friday accused Sudanese security forces of killing more than 100 people in indiscriminate machine gun attacks on villages in South Darfur over a three-month period. In a report covering January-March, U.N. High Commissioner for Human Rights Louise Arbour called on the government to carry out an independent investigation into the attacks near Nyala. "In all instances, witnesses described hundreds of heavily armed attackers, many of who were identified as Border Intelligence personnel," the report said, citing "consistent" testimony gathered by U.N. human rights officers. "During all the incidents, attackers fired indiscriminately from the outskirts of the settlements with heavy machine guns and rocket propelled grenades, before entering the settlements and shooting men," it said. The border intelligence guards, often recruited from the local population, are part of a secretive unit "known to be under the control of Military Intelligence," the report said. It said some attackers, described as wearing green or beige khaki uniforms, had left behind military identification cards. But the U.N. team had "not found evidence that the attackers were operating under the direct command of the government." At least 200,000 people have been killed and more than 2 million displaced since 2003 in an ethnic and political conflict triggered by a rebellion in Darfur. Rebels are fighting government troops and their Janjaweed militia allies. The United Nations is trying to hold Khartoum to an agreement to allow the world body to bolster African Union soldiers with a "hybrid" force of more than 20,000 troops and police in Darfur, a vast western region. LAND DISPUTE The latest violence, in an area known as Bulbul, stemmed from a long-simmering land dispute between two ethnic Arab groups, the Rizeigat Abbala and Tarjum, according to the 10-page U.N. report. It said Sudanese forces had sided with the Rizeigat Abbala in carrying out the attacks on Tarjum villages. "This is not the first dispute between members of these groups, however, what is particularly striking is the intensity of the fighting, the high number of casualties, and in particular, the involvement of Sudanese security personnel, weapons and vehicles' in the attacks on villages," it said. The most deadly attack had come on March 31 when more than 60 people from the Tarjum village of Morayajengay were killed. Attackers had also systematically looted the villages, particularly for livestock, before burning down the settlements. "The Office is seriously concerned that to date no effective action has been taken by the government to prevent the attacks or bring the perpetrators to justice," the U.N. report said. An independent investigation should "collect evidence to identify and prosecute those found to be responsible for the attacks as well as those who failed to prevent the attacks and protect the civilian population", it said. Sudanese authorities had received the report, according to U.N. human rights spokesman Yvon Edoumou. "They are fully aware of its contents and recommendations," he told a news briefing.
