An Ethiopian peacekeeper serving with the joint United Nations-African Union mission in Darfur (UNAMID) has died after being shot while traveling in the west of the troubled Sudanese region, the mission reported Sunday.

UNAMID issued a statement saying that the peacekeeper, whose name has not yet been released, died of his injuries on Thursday, following the shooting earlier that day in El Geneina, the capital of West Darfur state.

The slain peacekeeper and four Ethiopian colleagues were traveling in a UN minivan between El Geneina airport and the town itself when an unknown assailant at the side of the road fired at the vehicle.

A second peacekeeper is in a stable condition in hospital after sustaining an injury to an arm in the attack. UNAMID said no motive has been established for the killing, which is being investigated by both the mission's military police and by local Sudanese police.

More than 23,000 troops, military observers and police officers and nearly 4,500 civilians serve with UNAMID, which took over peacekeeping duties from an earlier AU mission at the start of 2008.

The force is tasked with protecting civilians, promoting an inclusive peace process and help ensuring the safe delivery of humanitarian assistance across Darfur, an arid region on Sudan's western flank.

Fighting and large-scale displacement has convulsed the region since 2003, when rebels took up arms against the Government, whose military forces responded with the support of allied militiamen.