The leaders of Nigeria and the Congo Republic emerged from all-night talks with Sudan's rebel leaders Sunday, with no real progress made on resolving the conflict in Darfur.

After meeting all night in the Nigerian capital Abuja, President Olusegun Obasanjo and Congo Republic's President Denis Sassou Nguesso pledged to hold further talks with the Sudanese groups.

The talks are aimed at ending more than three years of civil war before the April 30 deadline set by the African Union for a peace settlement.

Peace talks between Sudan's government and rebel groups have gone on for more than 18 months without any breakthroughs.

The fighting, involving rebels, government forces and Khartoum-backed Janjaweed militias in Darfur, has killed about 180,000 people and has left another two million homeless.

Some information for this report was provided by AP and Reuters.