An African Union official says two of the mission's peacekeepers have been killed in an ambush in Sudan's volatile Darfur region.

The acting head of the AU mission in Sudan, Jean-Baptiste Natama, said the two peacekeeping soldiers, as well as two civilian contractors, were killed Saturday during a surprise attack in South Darfur.

More than 6,000 African Union peacekeepers are deployed to the region.

Fighting between Sudanese rebels and government-backed Arab militia in Darfur has killed tens of thousands of people and driven more than two million others from their homes since 2003.

Some information for this report provided by Reuters, AP and AFP.