The United Nations' special envoy to Sudan told the Security Council on Thursday that Darfur is sliding into anarchy as government and rebel forces battle over control of the territory. The U.N. official, Jan Pronk of the Netherlands, said that U.S.-supported plans to send 3,300 African troops to halt the violence in the Darfur region are inadequate and that more than twice that number is needed to restore calm.

Pronk said that the Sudanese government is losing control of the Arab militias it equipped and recruited last year to counter black rebel forces and their kin, and that the militias have killed thousands and forced more than 1.8 million from their homes. But he blamed the rebel Sudanese Liberation Army for stirring up the latest round of violence by stepping up attacks against local police and robbing Arab traders of their camels, which are vital to Arab tribes. "They are provoking the militia to attack," he said in an interview after the meeting.

Pronk appealed to the 15-nation council to increase pressure on Khartoum and Darfur's rebels to strike a political deal ending the violence at a rare council meeting in Nairobi scheduled for Nov. 18-19. The meeting is being organized by John C. Danforth, the U.S. ambassador to the United Nations, to encourage Khartoum to sign an agreement with a separate rebel force it has been battling in another part of Sudan for more than two decades. Danforth hopes that such an accord will help lead to a peace deal in Darfur.

"I am afraid the situation in Darfur may become unmanageable unless more efforts are made, both at the negotiation table and on the ground," Pronk told the council. "Darfur may easily enter a state of anarchy -- a total collapse of law and order."

"We may soon find that Darfur is ruled by warlords," he said.

The worsening violence in Darfur poses a serious challenge to U.S. efforts to end what U.S. Secretary of State Colin L. Powell has described as a campaign of genocide there by Sudanese forces and the Arab militia it has sponsored.

Last month, President Bush authorized the use of two C-130 transport planes to ferry Rwandan and Nigerian troops into Darfur, bringing the number of African troops there to 670. The State Department has authorized more than $20 million to fund Los Angeles-based Pacific Architects and Engineers and Reston-based DynCorp International to give the Africans logistical support.

But the foreign forces have not contained the violence. Pronk said small groups of Arab fighters, known as the Janjaweed, have staged attacks on civilians in Darfur over the past month. Thousands more are regrouping for a military offensive against the rebels, he added.

Pronk said that although the links between Sudanese authorities and the militias are becoming "blurred," Sudan's military has incorporated police and Janjaweed militias into its operations in Darfur. African Union monitors are also investigating reports that Sudan bombed villages with attack helicopters in violation of commitments that the government has made to the United Nations.

Such action could constitute violation of two Security Council resolutions that threaten sanctions against Sudan if it does not crack down on militias. But Pronk told reporters that sanctions would be counterproductive.