Thousands of refugees welcomed the U.N. secretary-general in Kalma Camp, the biggest in Darfur, before he traveled to Labado, also in South Darfur state, to wander among burned huts and speak to worried owners who have started returning home.

"Now we are back but still we don't have security and we feel unsafe," Murra Ahmed told Annan after she described how five government planes had bombed Labado and driven her out.

South Darfur state has seen some of the worst recent violence in a three-year conflict the United Nations says has killed tens of thousands and forced 2 million from their homes.

African Union (AU) commander in Labado, Colonel Mohamed, briefed Annan and his delegation on the attack on Dec. 17 that set Labado ablaze and killed 105 people.

AU monitors verified that there was a government bombardment of Labado. The government has not disputed the finding.

Mohamed, who did not give his full name, said he wanted an expanded mandate for the AU from its present monitoring force with limited powers to protect civilians, to full peacekeeping status.

For now, the more than 2,300 AU troops are to protect the military observers in the troubled region. Hundreds of civilian police are also being deployed to the refugee camps.

"We don't need protection for the military observers, we need to protect the civilians," Mohamed told Reuters after the briefing. "We need a peacekeeping mandate."