With Darfur's remaining rebels still refusing to sign a peace deal, fighters from African tribes that were united against the Sudanese government have turned on each other.
Around Tawilla, thousands of civilians have been displaced since the beginning of the year following deadly violence between two ethnically divided factions of the Sudan Liberation Army (SLA), Darfur's largest rebel movement.
In what has become a turf war for control of rebel-held territory, gunmen on pick-up trucks and horseback have been burning huts, killing, looting and even raping women, in raids just as deadly as those of the Arab "Janjaweed" militia.
Villages that had been emptied due to raids by government forces are once again deserted. Camps for displaced people on the outskirts of town lie abandoned, their terrified former residents having barricaded themselves in makeshift shelters against the razor wire surrounding the African Union peacekeepers' base. All but one international nongovernmental organization have left.
"Initially the trouble here was the government forces," said an AU military observer based in Tawilla, two hours' drive west of the state capital, El Fasher. "But now these different SLA groups fighting each other have become the problem," he said.
Fighting between the African rebels reached its peak before the peace agreement was signed on May 5 by Sudan's government and the larger faction of the SLA, which was desperate to make territorial gains before the ceasefire.
Hopes of an end to the rebels' mutual enmity, which has added another layer to an already muddled conflict, were dashed again on Monday when the SLA faction led by Abdel Wahid ignored an extended deadline to accept the Darfur peace agreement. A third, smaller, group, the Justice and Equality Movement, is also holding out. Wahid is demanding more detailed provisions on compensation for the war's victims and disarmament of the Janjaweed militia. There are serious doubts as to whether the peace accord can hold. Negotiators have again extended the deadline for the rebel groups to join the agreement to May 31.
On Tuesday the UN security council passed a resolution to speed up planning for a UN peacekeeping force in Darfur and threatened sanctions against anyone who opposed the May 5 accord. On Monday the African Union agreed to transfer authority for its 7,300 strong peacekeeping force to the UN by the end of September.
The latest twist in the Darfur crisis follows a major falling out late last year in the leadership of the SLA, a broad-based guerrilla movement formed to protest against the region's marginalization by the Arab-dominated regime in Khartoum.
Minni Arcua Minnawi, the group's secretary-general, took with him the larger share of the fighters and weapons. Most of his men are Zaghawa, a cattle-herding tribe. Wahid, the SLA chairman, and a member of the sedentary Fur, Darfur's largest tribe, was left with a smaller force but a large support base.
"We thought we would meet up in Khartoum, as we still had the same objectives," said Commander "Tiger" Muhammad, from the Wahid faction, who arrived in the deserted village of Tina yesterday with several dozen of his fighters.
Some of his men took part in the 2003 attack on government forces in El Fasher that helped spark the Darfur conflict. Retribution came quickly to Tawilla, as government forces attacked African tribes.