NAIROBI: The drought and famine in Somalia have killed more than 29,000 children under the age of 5, according to U.S. estimates, the first time such a precise death toll has been released related to the Horn of Africa crisis. The figures came as experts warned the famine, currently ravaging parts of Somalia, including the capital Mogadishu, is likely to persist for the rest of the year and engulf all of the country’s south.

The whole of southern Somalia is already suffering severe food shortages due to a harsh drought affecting several Horn of Africa countries, causing what the U.N. called “the most severe humanitarian crisis in the world today and Africa’s worst food security crisis since Somalia’s 1991-92 famine.”

“Famine is expected to spread across all regions of the south in the coming four to six weeks and is likely to persist until at least December 2011,” said the U.N.’s Food Security and Nutrition Analysis Unit.

The United Nations has said previously that tens of thousands of people have died in the drought. The U.N. says 640,000 Somali children are acutely malnourished, a statistic that suggests the death toll of small children will rise.

Nancy Lindborg, an official with the U.S. government aid arm, told a congressional committee in Washington Wednesday that the U.S. estimates that more than 29,000 children under the age of 5 have died in the last 90 days in southern Somalia. That number is based on nutrition and mortality surveys verified by the United States Centers for Disease Control and Prevention.

At least 2.8 million people including 1.25 million children are in dire need of assistance in southern Somalia, U.N.’ s Office for the Coordination of Humanitarian Affairs said. Nearly half of Somalia’s estimated 10 million people require humanitarian aid.

Getting aid to Somalia has been made more difficult because Al-Qaeda-linked militants control much of the country’s most desperate areas. Al-Shabaab has denied that a famine is taking place, and won’t give access to the World Food Program, the world’s biggest provider of food aid.

Tens of thousands of refugees have fled south-central Somalia in hopes of finding food at camps in Ethiopia, Kenya and in Mogadishu.

Hundreds of millions of dollars have been donated to fight the hunger crisis, but the U.N. says it needs hundreds of millions more.

Some $2.4 billion is required to assist 12 million people, but only half of that amount has been received.

The African Union, which has contributed $500,000, Thursday postponed to Aug. 25 a donors conference to raise funds for the crisis. The meeting was initially scheduled to take place next week. No explanation was given.

The latest famine declaration “confirms our concerns over the increasing severity of the crisis facing Somalia, especially internally displaced people,” United Nations humanitarian coordinator for Somalia, Mark Bowden, said.

Bowden urged “all parties to support an urgent scale up of assistance so that we can save the lives of those who most need our support at this critical moment.”