GENEVA (Reuters) - A survey of food security in Yemen has found more than 15 million people are in a “crisis” or “emergency” situation and that number could hit 20 million without sustained food aid, the U.N. World Food Programme said in a statement on Thursday.

The survey, carried out by Yemeni and international experts in October according to an international system for classifying food crises, also found about 65,000 in a food “catastrophe” or near famine levels, mostly in conflict zones. That number that could rise to 237,000 if aid does not get through, the WFP said.