The top United Nations official for humanitarian affairs says Arab militias in Western Sudan's Darfur region are conducting an ethnic cleansing campaign to drive out the black population and U.N. officials have witnessed the attacks. The U.N. official urged the Security Council to pay greater attention to the crisis.

After briefing the Security Council, the U.N.'s Emergency Relief Coordinator Jan Egeland told reporters that humanitarian workers had documented the killing of 212 civilians last month in western Sudan and over one hundred people were injured. But he said the actual figures are much higher and U.N. humanitarian workers have witnessed the brutality.

"I have colleagues from my office seeing, in desperation, people getting killed, gang raped, abused and not being able to do anything to help, then reporting it to police and army and then they say, no, we can not, or will not [help] or they investigate it 48 hours later," he said.

Mr. Egeland would not compare the situation in western Sudan to Rwanda, where ten years ago the Hutu majority unleashed a genocide that led to the killing of an estimated 800,000 minority Tutsis. The United Nations, along with the international community, failed to act to end the violence during the 100 days of mass killings.

But the U.N. official said the violence in Sudan has caused one of the world's worst humanitarian crises and urged the Security Council pay greater attention to the crisis. "I would say it is ethnic cleansing, but it is not genocide, and we should avoid it escalating further," he said.

The U.N. fficials said Arab militias, including the group known as "Janjaweed" are carrying out an organized campaign of destruction to make villages uninhabitable for black Africans in Darfur. Since last year Sudanese forces and Arab militia allies have been trying to put down a rebellion in the regiom.

Mr. Egeland blamed the government of Sudan for failing to stop the violence. "I have no reason to believe that the government is actively planning it. But I have reason to say that far too little is done to stop it. Therefore, it seems that it is being condoned," he said.

Mr. Egeland recommended that the Security Council exert pressure on the parties in the region to reach a ceasefire in peace talks that began this week.

On Thursday, the New York-based monitoring group Human Rights Watch released a report accusing Sudanese government and Arab militia forces of killing, raping and targeting black civilians in Darfur. The Security Council released a statement expressing concern about the massive humanitarian crisis and called on the government of Sudan and opposition groups to reach a ceasefire and a political settlement.

The U.S. envoy, Stuart Holliday, also called for an immediate cease-fire and open access for the delivery of humanitarian aid. The United Nations says the crisis in western Sudan has created about 750,000 internally displaced people and about one-third are in need of acute assistance.

The international organization is sending a fact-finding mission to the Darfur region to investigate the allegations of widespread atrocities.