The attack happened on October 23 about 15 kilometres (nine miles) southwest of Nyala, Sudan's second largest city, the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) said in its latest weekly bulletin, issued late yesterday.
It said the head of the Sudanese Al-Sugia Charity Organisation, a non-governmental group, was killed by unidentified gunmen.
"Another staff member of Al-Sugia on board the NGO vehicle and a police officer were injured when the gunmen ambushed and hijacked the vehicle," OCHA said.
In June a Sudanese nurse working for an international aid agency was killed when a stray bullet went through the wall of his home in a camp for displaced people in Central Darfur.
More From This Section
A 10-year-old rebellion continues in Sudan's western region of Darfur but an upsurge of violence this year is mainly due to inter-ethnic militia fighting, most of it Arab against Arab.
Hundreds have been killed and hundreds of thousands displaced since January.