Horseback raid on Darfur troops

There are numerous armed groups operating in Darfur

Armed men on horseback have attacked and stolen the weapons of Nigerian UN peacekeepers in Sudan's Darfur region.

The joint UN-African Union troops were ambushed by up to 60 men armed with AK-47s and rocket-propelled grenades on Wednesday, the Unamid peace force said.

It is not clear who was behind the attack, which has been made public for the first time.

The UN took joint control of the force in January but has not been able to bring peace to the region.

It has just 9,000 of the planned 26,000 troops.

"We are a peacekeeping organisation but there is no peace on the ground to keep," Unamid spokesman Noureddine Mezni told Reuters news agency.

He said the incident had been kept quiet while attempts were made to identify the attackers.

"We have bandits and we have armed groups and we have the [rebel] factions. With our very limited number of troops, it is not an easy job."

The attack happened near the West Darfur capital, Geneina.

The conflict began five years ago, when rebels took up arms in protest at alleged government discrimination against the region.

Pro-government Arab militias have been accused of widespread atrocities against the black African population.

But the rebel groups have split into numerous different factions, making a settlement difficult.