"The southern part of Somalia would be at high risk of famine conditions, high risk meaning we estimate an over 50 percent probability it's going to happen," Haan said.

"If our high risk prediction is correct, it would be comparable to what we saw in '93 to '94 in Somalia."

Tens of thousands of Somalis perished in a famine that decimated the country in the early 1990s.

Since the ousting of strongman Mohamed Siad Barre in 1991 hundreds of thousands have died from famine, disease and conflict as the country plunged into anarchy.

There are at least 1.7 million Somalis affected by drought of a population of 10 million.

Haan said using the technical definition of famine as four deaths per 10,000 people per day, Somalia could see 12,000 deaths per month in those devastated areas.

"This is manifesting itself as what could be a major humanitarian catastrophe of historic nature," Haan said.

Hundreds of people and tens of thousands of livestock have died from hunger and thirst across a vast region encompassing some of Africa's poorest and most arid zones.

Experts have said recent heavy rains in central and east Africa were not the start of the rainy season and drought conditions would persist.

The United Nations estimates that at least 6.25 million people are in need of immediate food aid across east and central Africa because of drought.

Haan said that by mid-May it should be known for certain where the situation is heading, but conflict could exacerbate the problem and create famine conditions.