Four peacekeepers were slain and eight injured in an ambush in West Darfur, the African Union and United Nations joint mission to the troubled region said Wednesday.
It remains unclear who was behind the Tuesday evening attack less than a mile and a half from the mission regional headquarters, which involved a Nigerian military patrol. Hit with heavy fire from several directions, the peacekeepers returned fire, according to a brief statement released by the mission.
United Nations Secretary-General Ban Ki-moon on Wednesday urged the government of Sudan to investigate the attacks and prosecute those responsible. He also expressed condolences for Nigeria.
The Sudanese region has been wracked for nearly a decade by a conflict that began with rebels waging war against the government in Khartoum, complaining about the marginalization of the western region.
President Omar Hassan Ahmed Bashir is wanted by the International Criminal Court on charges of murder and other war crimes committed during Sudan's crackdown on the rebellion, estimated to have killed 35,000 people. At least 100,000 more people are believed to have died from disease and hunger caused by the campaign.