Large swathes of farmland are submerged and food stocks have washed away after torrential rain pounded the Horn of Africa country for several days, swelling the Juba and Shabele rivers.
"These are the worst floods to affect the region in the last seven years," Sheikh Abdisalan Hassan, chairman of the middle Shabele Islamic administration, told Reuters.
"Children have been washed away while others have died of starvation. People badly need food and safe drinking water. I request aid agencies to help these poor people," he said.
The downpours have also affected villagers in Ethiopia, where at least 68 people have died and more than 279,000 people have been displaced from their homes.
Aid workers expect the death toll in Somalia to rise as thousands of poor farming families sleep out in the cold and are exposed to malaria and water-borne diseases. The carcasses of livestock still lie in stagnant water.
Somalia, one of the world's poorest countries, plunged into anarchy in 1991 after a dictator was overthrown by clan warlords. Since then tens of thousands have died from violence and hunger.
Fears of an all-out conflict in Somalia, which could enflame the Horn of Africa, have risen in the last few weeks after Arab League-sponsored peace talks between the Islamist movement and the Western-backed government of President Abdullahi Yusuf.
The powerful Islamists control the capital, Mogadishu, and most of southern Somalia after defeating US-backed warlords.
"FEEDING ON GREEN LEAVES"
In Huruwaa village, 145 km (90 miles) north of Mogadishu, some 47 homeless families sheltered on hilly ground between a flooded Shabele river and a pool of rain water.
Khadija Adan, a mother of four, said her family had not had food for close to two days.
"We have been feeding on green leaves for the last 18 hours," Adan said in Huruwaa while suckling her baby boy. "If I could get utensils, I could cook the leaves for my children." Ibrahim Haji Ali, deputy chairman of lower Shabele region, said many people could not be traced due to driving rains.
"Over 20 (people) have died in our region alone. There must be so many other dead people since it has been raining constantly for days," he said.
Juba and Shabele are the most agriculturally productive regions in Somalia and their produce is transported to other parts of the country.
"Times change very fast," farmer Nuh Isse said. "I was rich five days ago preparing to harvest my fruits but now am begging to save my life. This is the worst disaster."

Copyright Reuters, 2006