WASHINGTON -- The 6,700-member African Union force sent to help prevent genocidal attacks in the Darfur region of Sudan has been unable to protect its own soldiers, let alone the 2 million displaced people living in camps there, humanitarian groups and regional specialists say.

The force, dispatched last year to monitor an unraveling cease-fire in an area roughly the size of France, has been targeted by government-backed militias, which attracted worldwide condemnation for attacking civilians, and by rebel groups that are fighting the government.

Two groups asserted this week in separate reports that the African soldiers do not have enough equipment or soldiers to protect themselves and they lack a mandate to take the offensive -- even when they have advance warning of planned attacks against civilians.

The reports quoted members of the force.

In the past two months, at least five African Union soldiers have been killed and 38 kidnapped.

"Things have been getting much, much worse now that attackers have seen there is no real consequence for targeting the African Union troops, internally displaced people or the aid community," said Sally Chin of Refugees International, a Washington-based humanitarian group that issued a report calling for the African Union to increase its force in the short run and eventually hand over the mission to the United Nations.

The Brookings Institution, a think tank in Washington, D.C., released a similar report this week.

It called for 20,000 African Union troops on the ground, or for the United Nations, the European Union or NATO to take over.