The World Food Program (WFP) says famine may be looming in South Sudan where citizens are running away from fighting and leaving their crops to rot in agricultural fields.

"Malnutrition is already above the 15 percent emergency level in seven out of South Sudan's 10 states, and about 30 percent in two of them - Unity and Northern Bahr el Ghazal,"WFP spokeswoman Bettina Luescher said.

“Up to 4 million people – over a third of the population in South Sudan – are severely food-insecure, meaning a third of the country doesn’t know where the next meal is coming from," she said. "The current level of malnutrition is unprecedented."

According to the aid group, widespread fighting between government troops and rebel fighters means people cannot harvest crops.

The relief agency pointed out that it is conducting air drops and air deliveries because many roads are impassable in the country, saying one UN aid convoy of 38 trucks carrying food aid for 52,000 people for a month, did reach Yei town on Friday.

Over 1 million refugees mostly women and children have streamed out of the country, according to WFP.