Washington is pressing the rebel Sudan People's Liberation Army (SPLA) and the government to reach a final deal soon. US Secretary of State Colin Powell said on Tuesday he was optimistic about a comprehensive agreement this month. 

The two sides are holding what should be their last round of talks in Kenya. But with several key issues still under discussion, including carving up power and wealth from lucrative oilfields, a final deal may not be imminent.

The conflict, which erupted in 1983, broadly pits the rebels in the south against the government in the north. About two million people have died as a result of the war, mainly due to disease and famine.

A group of nearly 50 Sudanese women marched in Nairobi on Tuesday to demand that the African Union should come up with measures to force Khartoum to keep all its promises in the final deal.

“We are asking the Arab League and the African Union to include measures to pressure the government of Sudan to honour the agreement,” said Aguil Dechut Deng of the SPLA. “If they break the agreement, we demand economic and diplomatic sanctions against Khartoum.”

Darfur conflict
 
While negotiations continue to end the war in the south, a conflict has been growing in the west of Africa's largest country where some insurgents say they have turned to arms after seeing the SPLA's success in securing talks with the government.

UN is voicing concerned at abuses
against civilians in the west

UN Secretary General Kofi Annan on Tuesday expressed worry over the troubled arid region of Darfur, where reports say pro-government militias have been running amok.

"The secretary general is alarmed at the rapidly deteriorating humanitarian situation in the Darfur region of Sudan, and by reports of widespread abuses against civilians, including killings, rape and the burning and looting of entire villages," his spokesman Fred Eckhard said.

Relief workers say pro-government Arab militias have run rampant since being recruited to crush a rebellion that erupted in February over the region's economic neglect.

The leader of one of two main groups in Darfur said he had spoken to SPLA leader John Garang and urged him to include other areas in any future deal.

SLA peace talks with the government, due to resume in Chad this week, have been postponed after the government complained of a ceasefire violation by the rebel group.