JUBA, South Sudan (AP) -- The United Nations says hunger in South Sudan has reached "unprecedented" levels, with nearly 5 million people suffering from severe food insecurity.

The UN's Food and Agriculture Organization said Friday that without a return to stability that will allow agricultural production to continue, "the situation could rapidly become catastrophic."

The World Food Program has said both South Sudan's government and the opposition have held up food shipments in parts of this East African country, which is trying to recover from civil war.

Roughly $30 million in supplies were looted from warehouses of the two UN agencies during clashes between government and rebel forces in July,