NAIROBI, Kenya (AP) — A new report from a monitoring group says famine is at risk of spreading to a third county in South Sudan.

The Famine Early Warning Systems Network says starvation is likely to occur in Koch county.

Famine already has been declared in the counties of Leer and Mayendit, with a million people said to be at risk.

The new report says famine is likely to spread during the lean season for farmers from July to September. It says that without the presence of humanitarian aid, famine could be declared in even more areas.

The East African nation's civil war, now in its fourth year, has blocked aid to some regions.

The combination of fighting and famine in the world's youngest country has created one of the world's largest humanitarian crises.