Nairobi - The number of people going hungry in eastern Africa is rising dramatically especially in drought-hit Ethiopia, the United Nations said on Thursday, amid conflict as well as floods and failed rains due to El Nino.El Nino, a global weather pattern that periodically wreaks havoc, is expected to last until early 2016."Due to El Nino, food insecurity is forecast to worsen over the coming months, especially in Ethiopia," the UN Office for the Coordination of Humanitarian Affairs said in a report."By the beginning of 2016 the number of people who are food insecure and in need of humanitarian assistance is expected to increase to 32.1 million," it read, adding that "up to two million people could be affected by flooding".Since May, numbers in need have already risen by 6.7 million, from 18.5 million to 25.3 million people, the report added.While some countries - including Sudan, Eritrea, Ethiopia and Djibouti - could see drier conditions, other countries including Kenya, Somalia and Uganda are at risk of floods.Over 90 000 people in war-torn southern Somalia have already been hit by weeks of severe flooding, almost half of them forced from their homes, the UN said.But in neighbouring Ethiopia, El Nino has "wreaked havoc" on summer rains needed by farmers for their crops, with around 8.2 million people needing food aid, nearly double the number in need six months ago."This comes on the heels of failed spring rains, and has driven food insecurity, malnutrition and water shortages," the UN said, with "fears that this figure will continue to grow."El Nino comes with a warming in sea surface temperatures in the equatorial Pacific, and can cause unusually heavy rains in some parts of the world and drought elsewhere.