Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. July 26, 2011 Delays Hold Up UN Food Airlift to Horn of Africa VOA News Internally displaced Somali women queue to receive food-aid rations at a distribution center in a displaced persons camp in the Somali capital Mogadishu, on July 26, 2011 Photo: AFP Internally displaced Somali women queue to receive food-aid rations at a distribution center in a displaced persons camp in the Somali capital Mogadishu, on July 26, 2011 The U.N. World Food Program says an airlift of food to the drought-stricken Horn of Africa has been postponed until at least Wednesday. The airlift was due to begin Tuesday, but a WFP communications officer tells VOA's English to Africa service the flights have been held up by logistical problems in Kenya. The WFP said Monday that planes will carry food to Somalia's capital, Mogadishu, eastern Ethiopia, and northern Kenya, near the Somali border. Definition of Famine: The word famine is a term that is not used lightly by humanitarian organizations. The United Nations describes a crisis as a famine only when the following conditions are met: * Malnutrition rates exceed 30 percent * More than two people per 10,000 people are dying each day * Severe lack of food access for large population Current Famine: Almost half of Somalia's population, 3.7 million people, are affected by the current crisis with malnutrition rates in southern Somalia the highest in the world, surpassing 50 percent in some areas. The United Nations says it is likely that tens of thousands have already have died, the majority of those being children. The drought that has led to the current famine in parts of Somalia has also affected people in Kenya and Ethiopia. Previous Famines in the Horn of Africa: * Somalia 1991-1992 * Ethiopia 1984-1985 * Ethiopia 1974 The United Nations says "massive" action is needed to save millions of people living in the Horn of Africa from starvation. U.N. and U.S. officials have said more than 11 million people are in need of emergency aid to survive. A donors' conference will be held Wednesday in Kenya's capital, Nairobi. The U.N. is seeking pledges of $1.6 billion to help drought victims, many of whom are children. On Tuesday, the U.N. refugee agency said tens of thousands of starving Somalis are fleeing their homes and coming to the capital, Mogadishu, in search of food and water. The agency said 100,000 Somalis have arrived at Mogadishu-area camps in the past two months, and continue to come at a rate of 1,000 per day. It said hundreds of thousands of others have fled to camps in neighboring Kenya and Ethiopia. The U.N. formally declared a famine in two regions of southern Somalia last week. Access to southern Somalia has been hampered by the militant group al-Shabab, which controls large sections of the region and has denied that a famine is taking place. .