The top United States diplomat to Africa says there needs to be an "independent and credible" investigation into the Sudanese military's violent dispersal of a protest camp in Khartoum last week.

Tibor Nagy said the deadly crackdown "constituted a 180 degree turn in the way events were going with murder, rape, pillaging, by members of the Security Forces."

Nagy, the U.S. assistant secretary of state for Africa, said Sudan risks sliding into Libya or Somalia-like chaos. Speaking in Ethiopia late Friday after a two-day visit to Sudan, he said both the military council and protest leaders "absolutely distrust each other."

Protest organizers say the crackdown killed over 100 people in the capital and across Sudan, but authorities have offered a lower death toll of 61, including three security forces.