Drought in Ethiopia has caused food shortages, killed livestock and more than doubled the number of people needing urgent humanitarian aid to 5 million, the United Nations said on Friday.

"Seasonal rains have been poor or have failed in many parts of Ethiopia with dramatic effects on harvests in crop-producing areas," said Elisabeth Byrs, a spokeswoman for the UN Office for the Coordination of Humanitarian Affairs.

The United Nations is seeking US$325 million to provide nearly 400,000 tonnes of food aid as well as health and other assistance through November to people in Ethiopia's hard-hit south and southeastern regions, which border Somalia and Kenya.

Some 4.6 million people are now in need of assistance, compared to 2.2 million before the drought took hold, Byrs said.

As many as 75,000 children are already suffering from acute malnutrition and illness as a result of the drought, which the United Nations said has compounded pressure on poor Ethiopians squeezed by an increase in the global prices of cereals and other foods.