The number of people needing humanitarian aid in Somalia has leapt 17.5 percent in a year to 3.76 million or half of the Horn of Africa country's population, an authoritative study showed on Tuesday.
The Food Security and Nutrition Analysis (FSNAU) report said three-quarters of those in need were concentrated in central and southern regions where fighting between the government and armed opposition groups was heaviest.
An intensifying humanitarian crisis will feed fears in the region and beyond that the chaos in Somalia could spill across its borders.
Cindy Holleman, chief technical advisor of the Somalia FSNAU, told Reuters that the increase in the number needing help from 3.2 million in August 2008 showed a serious deterioration in the emergency food security and nutrition situation.
"More worrying is that the escalating fighting and conflict is occurring in the same areas where we are now recording the greatest problems of food access and malnutrition," she said.
"This will not only place additional burdens on the people already in crisis, but will also make it difficult for humanitarian relief to reach the vulnerable populations most in need of humanitarian and life-saving interventions."
Violence has killed more than 18,000 Somalis since the start of 2007 and driven another 1 million from their homes.
The FSNAU, set up by the U.N.'s Food and Agriculture Organisation to provide aid agencies with reliable data from Somalia, said one in five children were now acutely malnourished, and one in twenty were severely malnourished.
These rates were among the highest in the world, it added.
Included in those needing aid were 1.4 million rural people affected by a severe drought, 655,000 urban poor struggling with very high food and non-food prices, and more than 1.42 million internally displaced people (IDPs) who have fled the conflict.
The number of IDPs has risen 40 percent in just six months.
It said the epicentre of the crisis was in Mudug, Galgadud, Hiran and Bakool regions of south and central Somalia, which have been afflicted by drought for two and a half years.
"Livestock herds have been decimated and destitute pastoralists are gathering in main villages and towns in search of assistance," the report said.
"The depth of the crisis in these areas is severe with up to 75 percent of the total population in humanitarian emergency."
Given the escalating civil war, the FSNAU also issued an early warning for an even greater deterioration in the humanitarian situation depending on the extent of the fighting.