The London-based human rights group said almost all of the 65 camps housing more than 2 million Darfuris driven by their homes by five years of conflict were awash with weapons because inmates felt vulnerable to attack.

"Internally displaced people live in a protection vacuum," Amnesty said in a report, adding that the now defunct African Union peacekeeping force sometimes mounted only one patrol a day in the entire region.

The army and police were seen as "antagonistic rather than protective" by the Darfuri camp residents, Amnesty said.

Three weeks after the joint United Nations-African Union UNAMID peace force began operating in Darfur, "urgent steps must be taken to ensure that the government of Sudan removes all impediments to the complete deployment of UNAMID forces," Amnesty said.

The government has refused to allow non-African troops to join the mission and has made a series of demands that have the effect of hampering operations of the force, which is intended to reach a total strength of 26,000.

Amnesty cited cases of attacks, rapes and harassment of displaced people in Darfur by rebel movements, militias, government forces and bandits and warned that the camps were at breaking point.

Young men who had languished in the camps for five years with no hope for the future were taking up weapons.

"There is a lot of anger among them and they don't know how to cope with it, former aid worker Seifeldin Nimer said in the report.

"This younger generation, with little education, no future or work, the only thing they can think of is to take a weapon."

International experts estimate some 200,000 have died in Darfur and two-thirds of the population now depend on the world's largest humanitarian operation for survival.

The fighting started in 2003, after mostly non-Arab rebels took up arms accusing central government of neglect. Khartoum mobilised mostly Arab tribes to quell the revolt, many of whom were never disarmed.

Since then, a breakdown of law and order caused by inter-tribal clashes, infighting among rebels and disorderly government forces has created a climate of impunity in Darfur where the gun rules, Amnesty said.

The rights group said Khartoum must "end impunity for human rights abuses (and) ensure that anyone who attacks internally displaced people is brought to justice".

When the peacekeeping force is operational, Amnesty said it should deploy near the camps and patrol regularly to deter attackers from preying on helpless Darfuris.