Unidentified assailants have shot and killed three lorry drivers contracted by the UN World Food Programme (WFP) in the war-scarred western Sudanese region of Darfur, the organisation said.

Two of the men, who were killed on 16 October, worked for the Abbarci trucking company, WFP said.

"WFP is deeply saddened and shocked by the killings of these brave men, who knew the dangers they were facing but continued to work tirelessly to alleviate suffering and bring food to the hungry in Darfur,” said Kenro Oshidari, WFP Sudan representative.

Two of the drivers were murdered in South Darfur on the road between the town of Ed Daien and the city of El Obeid. The men were returning to El Obeid after delivering supplies. The third man, also an employee of Abbarci, was killed on 12 October in South Darfur on the road between the state capital Nyala and the city of El Fasher, capital of North Darfur.

Earlier in October aid workers warned that an upsurge in violence in Darfur was further restricting the ability of the few humanitarian workers left to reach thousands of vulnerable civilians.