"Rates of malnutrition in most of southern and central Somalia are above emergency threshold levels of 15 percent and in many areas greater than 20 percent and increasing," said an analysis prepared by FAO's Food Security Analysis Unit (FSAU).
"The number of severely malnourished children is continuing to increase in many urban towns and among internally displaced populations (IDPs)," according to the 2008 Post Gu Analysis Technical Series Report, released on 15 October.
"In the north, where malnutrition rates are normally low and stable, the nutrition situation is also now deteriorating."
Escalating insecurity, it added, had led to killings, violence, human rights abuses, and population displacement. It had also created an economic crisis with a wider, devastating impact on the broader population and humanitarian situation.
"The unfolding humanitarian disaster is widespread and the level of human suffering and deprivation shocking," the FSAU noted. One in six children under the age of five was acutely malnourished, it added.
Over the last seven months, civil insecurity and conflict has steadily worsened, especially in the southern and central regions. The current situation was the worst the country had experienced since the collapse of government in the early 1990s.
Overall, an estimated 3.25 million people or 43 percent of Somalia's total population would need humanitarian assistance until the end of the year - a 77 percent increase in the number of those in need since January.
This number is the result of a growing urban food security crisis, affecting more than 705,000 urban poor, and a deepening rural crisis reflected by a rise in the rural population from 850,000 early this year to almost 1.4m currently.
"In addition, the number of people displaced by conflict is continuing to increase and is now estimated at 870,000," FSAU noted.
According to the analysis, the situation has been compounded by the poor performance of the Gu rains, which resulted in below normal local cereal production, and deepening drought and water crisis in pastoral areas.
"Food prices are expected to remain high, and therefore food access for market dependent households, including urban, rural poor, and IDP populations will become increasingly difficult through December this year," it predicted.
In Central Hiran and Bakool regions, the caseload of severely malnourished children had doubled in feeding centres in Galgadud. Other areas showed a critical, deteriorating nutrition situation.
Lower and Middle Shabelle regions are the worst affected, including Mogadishu, where the number of affected has risen 62 percent from January to about 1.08 million currently.
The two regions host the largest concentration of new IDPs from Mogadishu and have the highest caseload of acutely and severely malnourished children in Somalia.
"The situation is due to the combined impact of delayed and poor Gu '08 rains, another season of below average crop production, exhausted rangeland conditions, persistent hyperinflation of food and non-food commodity prices," the FSAU said.
Other factors included reduced purchasing power, disrupted market and trade activities, and high levels of population influx and displacement due to escalating conflict.
In the north, an acute food and livelihood crisis was emerging as pastoralists struggle to cope with another season of below normal rainfall, deteriorated water and pasture conditions and soaring water and food prices.
"To cope, pastoralists are selling more animals, splitting families and migrating with their livestock to areas where water and pasture is available," FSAU observed.