The UN Human Rights Council accused Sudan's security forces Friday of "indiscriminately" killing more than 100 people in large-scale attacks in southern Darfur since January.

Uniformed officers of the Border Intelligence Guards carried out the attacks on villages in the Bulbul area near Nyala, said the report, which was recommended by Canadian Louise Arbour, the UN's high commissioner on human rights.

The report said the guards participated in eight raids carried out between January and March by the Rizeigat Abbala group against members of the rival Tarjum tribe.

"In all instances, witnesses described hundreds of heavily armed attackers, many of who were identified as Border Intelligence personnel," the report said.

"During all the incidents, attackers fired indiscriminately from the outskirts of the settlements with heavy machine-guns and rocket-propelled grenades (RPGs), before entering the settlements and shooting men found inside."

The latest attack was reported on March 31, with 60 people killed, the agency said.

The report concludes that Sudan is "failing to protect the human rights of the population in the Bulbul area, and in particular the right to life."

It calls on the Sudanese government to investigate the incidents and act to protect civilians from attacks.

World's largest humanitarian disaster

Rebels have been fighting the Sudanese army and the pro-government janjaweed militia in Darfur for four years, turning the region into the world's largest humanitarian disaster. More than 200,000 people have been killed and 2.5 million have been displaced.

There are 7,000 African Union peacekeepers in Darfur but they have been unable to stop the violence.

In April, UN Secretary General Ban Ki-moon said that he and Sudan's President Omar al-Bashir had agreed that a new United Nations-African Union joint peacekeeping force should be deployed in the region quickly.

Al-Bashir agreed in November to a three-phase UN plan to strengthen the African Union force, but has delayed allowing its implementation.