The United Nations World Food Programme has increased its aid operation in southern Sudan, where nearly one million people are facing severe food shortages.

In a statement, the WFP said it had launched an air operation from a new base at El Obeid in northern Sudan, to supplement existing air and road shipments from Kenya and Uganda.

It said sixteen thousand tonnes of food had been airlifted to the worst-hit region of Bahr al-Gazal on Saturday.Aid agencies estimate that the number of people needing food in southern Sudan is three times greater than first thought.

Last week, the medical charity, Medecins Sans Frontieres, said in some cases, half the severely malnourished children in its feeding centres were deteriorating because not enough food was getting through.