Gunmen have killed a peacekeeper and wounded another in an attack in North Darfur in western Sudan, the joint United Nations/African Union peacekeeping force (UNAMID) said on Thursday. "One peacekeeper was killed and another injured yesterday in ... North Darfur by unknown armed men," UNAMID spokesman Noureddine Mezni told Reuters. He said the shooting took place on Wednesday in the state of North Darfur. The killing brings to 10 the number of peacekeepers who have lost their lives in Darfur over the last three months. In October, one Nigerian sergeant was shot dead after up to 60 armed bandits ambushed his convoy. In early July, seven members of the under-manned force were killed and another 22 were wounded in an ambush by militia fighters in North Darfur. A week later, another Nigerian officer was killed in a car-jacking in west Darfur. The force is responsible for securing the violent region but is far short of its promised strength of 26,000 personnel.