Desperate plea by Darfur refugees

Men carried signs saying "We are looking for freedom and justice" and women screamed in welcome for the UN secretary general.

Annan listened as refugees complained about police and government-backed Arab militias they said had attacked, raped and killed their families inside the Kalma Camp in the south of Darfur.

The region has seen some of the worst recent violence in a three-year conflict that has killed tens of thousands and forced two million from their homes, according to latest UN estimates.

"Since we came to this camp they have killed 56 people," said Suleiman Abka Taha, a local tribal chief.

Taha, who was speaking in front of government officials, said he wanted Annan's guarantee that he would not be detained for what he said. Annan asked ministers for such a reassurance and got it.

Aid workers also told Annan that their organisations continued to suffer problems getting aid to the displaced in Kalma, but the presence of African Union (AU) police in the camp had helped.

Aid workers said that the Darfur emergency presented an extra challenge because insecurity rendered many areas out of reach. Donors needed to keep funds flowing for what the aid workers saw as "a long stretch ahead".

About 2,300 AU troops and hundreds of police are monitoring a shaky ceasefire in Darfur. Yesterday they kept control of the crowds who tried to swarm Annan's 20-car convoy.

Annan then talked alone to female rape victims in a reed hut guarded by AU troops in a section of the camp run by a Norwegian team.

A report by aid group Medecins Sans Frontieres in March said about 500 women or more had been raped in recent months, adding that their attackers were militiamen or soldiers. Khartoum, however, continues to deny widespread rape in Darfur.

As Annan was touring the camp, thousands of the refugees chanted: "Down, Down, oh Bashir," referring to Sudanese president Omar Hassan al-Bashir.

The leader of the Darfur rebel Sudan Liberation Movement said the situation of the refugees was particularly serious with the onset of rains that disrupt transport.

"I call on the United Nations and the secretary-general to take urgent and decisive steps to protect and return the displaced to their original homes and villages," Abdel Wahed Mohamed al-Nur said.

Last June, Kalma Camp housed 26,000 displaced in an area meant for 5,000. Now 110,000 Darfuris live in makeshift shelters in the area east of Nyala, the capital of South Darfur state. Aid workers said they were preparing a new site called al-Salam camp to house about 25,000 refugees to ease pressure on Kalma.

Annan also travelled to the town of Labado 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.

African Union commander in Labado, Colonel Mohamed, briefed Annan and his delegation on the attack on December 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.

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

Annan said: "I was very pleased to hear the local commander say that we need an expansion of the mandate. That to me is a clear indication of a commander who knows what he is here to do."

About half of the 60,000 people who lived in Labado have gone back to their ruined homes since the AU set up bases there. But the residents also want a bigger AU role to secure their future.

"Just a week ago they burned a village not three km [two miles] from here. The AU could see them coming," said Juma'a Eissa, one of the residents. "But they didn't stop it, they just made a report."

In Khartoum on Friday, Annan met top Sudanese officials about Darfur, which the United Nations has called the world's worst humanitarian crisis.

"We discussed the need for us to do everything we can to bring security to Darfur and ensure the farmers can go back to their land, plant it, cultivate and harvest their crops," Annan said after the meeting. "Otherwise we are going to have a major humanitarian effort which will stretch the capacities of the international community"

The secretary-general's three-day visit to Sudan followed his attendance at an international donors' conference in Ethiopia, where Annan said the world was facing a "race against time" to prevent Darfur's situation from worsening.

By Friday, donors had pledged $300m in cash and more in kind to help the AU expand its peacekeeping mission in Darfur.

The lack of help for southern Sudan reveals a growing gap between rhetoric and reality as the G8 industrial nations prepare for their summit at Gleneagles in July, where fighting Africa's poverty will be high on the agenda. Tony Blair aims to convince fellow G8 members to double aid to the continent as part of a rescue plan he unveiled earlier this year.

Donors promised $4.5bn to bolster the peace deal at a conference in Oslo in April, but warehouses at the Kenyan border town of Lokichoggio, used as a staging post for aid dropped by UN cargo planes, are almost empty.

At least 180,000 people have died - many from hunger and disease - and about two million others have fled their homes in Darfur to escape the conflict, which erupted when rebels took up arms against what they saw as years of state neglect and discrimination against Sudanese of African origin.

The government is accused of responding with a counterinsurgency campaign in which government-backed Arab militiamen, known as Janjaweed, committed widespread abuses.

Today, Annan will fly to the southern Sudanese city of Juba to assess the implementation of a peace agreement signed earlier this year between the government and rebels.