The African Union said today Sudan had started withdrawing troops in Darfur ahead of an evening deadline to end fighting there, but Khartoum said the pullout was conditional on the rebels halting attacks.
Darfur rebels denied Sudan was pulling back its troops.
Officials at AU-sponsored peace talks in Nigeria gave the two sides a 24-hour ultimatum yesterday to end ceasefire breaches after a massive military build-up in Sudan's western Darfur region over the last two weeks.
Sudanese Foreign Minister Mustafa Osman Ismail said in Khartoum the government was setting conditions for compliance with the deadline. He told reporters the rebels must withdraw from areas they have entered since an April ceasefire and must refrain from attacks on relief organisations, civilians and their property, and property of the state.
Sudanese forces will never withdraw from Darfur as a whole because a UN Security Council resolution gives the government responsibility for maintaining security there, he added.
General Festus Okonkwo, the Nigerian head of an AU team of 834 ceasefire monitors, said his efforts to mediate between government and rebels had yielded minimal results and Darfur was now a "timed bomb that could explode at any moment".
The conflict has already displaced 1.6 million people and killed tens of thousands in the vast, arid region. The rebels suspended the peace talks in Nigeria's capital Abuja on Monday to protest against Khartoum's offensive.
The AU said it would report any further ceasefire breaches to the UN Security Council. The United States, Britain and the United Nations also weighed in with warnings to both sides.
Darfur rebels took up arms in early 2003 after years of tribal skirmishes over scarce resources in the remote region. They accuse Khartoum of neglect and of using so-called Janjaweed Arab militias to loot and burn non-Arab villages. Khartoum denies arming the Janjaweed and calls them outlaws.
The United Nations has said Darfur, an area the size of France, is suffering from one of the world's worst humanitarian crises with 2.3 million people in need of aid.