The transitional government in Somalia is struggling to exert its control beyond a few blocks in the capital Mogadishu with the help of African Union peacekeepers.
The U.N. refugee agency said fighting near the border with Kenya, meanwhile, has displaced roughly 60,000 people in the region.
"Of the estimated 40,000 people displaced within Somalia, most are living under trees without shelter, water, food or any sanitation" Andrej Mahecic, a spokesman for the U.N. refugee agency, said in a statement. "To make matters worse, it has been raining for days, increasing the risk of an outbreak of disease."
At least 10 civilians were killed in clashes between militias loyal to the transitional government and al-Shabaab near the Kenyan border.
Kenya has reportedly sent its own forces to man border areas amid the latest violence.
The United Nations said last week it was considering sending permanent staff to Mogadishu as the transitional governments claims additional victories over al-Shabaab.