Two Rwandan peacekeepers were shot dead and three wounded in an ambush by unidentified gunmen near a market in Sudan's Darfur region Friday, the peacekeeping force said.
The attack was a reminder of the vulnerability of the under-equipped joint U.N./African Union UNAMID mission in Darfur and brought the number of its personnel killed by hostile action in two years to 19.
The attackers opened fire on a group of 20 Rwandan soldiers escorting a tanker to a water point on the outskirts of the north Darfur settlement of Saraf Omra at about 4:45pm (1345 GMT), the UNAMID force said.
"It was the worst kind of ambush -- an ambush in a crowd," UNAMID communications chief Kemal Saiki told Reuters.
"You have to praise the courage of the peacekeepers. They returned fire but they kept their heads and kept it under control. If they hadn't, we could have been facing many civilian casualties."
Two Rwandan soldiers were killed and three critically wounded, he said. The survivors were airlifted to a hospital in north Darfur's capital El Fasher.
The attackers, armed with automatic weapons, escaped on foot and peacekeepers believed at least one was wounded, Saiki said.
He added that it was unclear why they launched the attack, which took place near houses and a market not far from a Sudanese government checkpoint about 2 km (one mile) from a UNAMID base in Saraf Omra.
"The men were wearing a mixture of uniforms and civilian clothes. They may well have been trying to snatch a vehicle," he said.
Law and order has collapsed more than six years after mostly non-Arab rebels took up arms against Sudan's government, accusing it of neglecting Darfur.
Early fighting that peaked in a government counter-insurgency campaign has subsided and the remote western region has been caught up in a free-for-all involving bandits, rebel splinter groups and rival tribes.
UNAMID, which says it has lost 108 of its vehicles to car-jackings, is responsible for keeping the peace in a territory the size of Spain.
It is still far short of its promised strength of 26,000 and lacks equipment including helicopters, with observers blaming a mixture of Khartoum obstruction and U.N. bureaucracy. Saiki said there were now about 17,800 soldiers and police on the ground.
A U.N. report last month accused the Sudanese army of harassing and threatening UNAMID peacekeepers in Darfur.
Sudan's Foreign Ministry summoned the deputy head of the force Thursday to protest against the report, the state news agency Suna reported.