Banditry in Darfur has prevented the delivery of sufficient food stocks to the western Sudanese region, thereby forcing the UN World Food Programme (WFP) to reduce monthly rations, the agency said.

The rations, which benefited 2.4 million people in March, will be halved per person per day from May, WFP spokesman Peter Smerdon said on 17 April.

So far this year, 60 WFP-contracted trucks have been hijacked in Darfur, of which 39 are still missing. Twenty six drivers remain unaccounted for, while one was killed last month.

As result, food deliveries have dropped to 900 tonnes per day from 1,800 tonnes a year ago.

"Attacks on the WFP food pipeline are an attack on the most vulnerable people in Darfur," Josette Sheeran, WFP Executive Director, said in a statement on 17 April.

"With up to three million people depending on us for their survival in the upcoming rainy season, keeping WFP's supply line open is a matter of life and death," she added. "We call on all parties to protect the access to food."

WFP appealed to rebel factions in Darfur to ensure security on the roads and to respect the neutrality of humanitarian workers.

"If the security situation on the roads improves, we will be able to restore the ration levels," said Kenro Oshidari, WFP Representative in Sudan.

The announcement followed UN Secretary-General Ban Ki-moon's latest report on Darfur, in which he said prospects for a negotiated political solution to the crisis had become remote.

Both the Sudanese government and rebels appear determined to pursue a military solution, while the international community had failed to supply helicopters and other logistics to the under-staffed African Union-UN Hybrid Operation in Darfur (UNAMID).

"I am extremely disappointed in the lack of progress on all fronts," the Secretary-General said in the report, which covers UNAMID’s operations for three months.

"The parties appear determined to pursue a military solution, the political process stalled, the deployment of UNAMID is progressing very slowly and continues to face many challenges, and the humanitarian situation is not improving."

He described as grave the implications of the current security situation for Darfurians. Attacks on food convoys and general violence were hindering aid provision, while sexual and gender-based violence in and around camps for internally displaced persons was high.

UNAMID was set up in 2007 with a projected strength of 26,000 military and police personnel, but it has only 10,600 in the field, including 1,400 civilians.

Aid agencies estimate that 200,000 people have died since conflict erupted in Darfur in 2003, while 4.5 million have been directly affected.