People who have fled the drought in Somalia to camps near the capital Mogadishu have now been hit by days of heavy rain.
Aid workers say five people, including three children, had died of exposure. A doctor told the BBC that people could not find shelter from the cold rain.
The victims have been displaced by a drought that has devastated large parts of the Horn of Africa.
Some 10 million people are said to be affected across the region.
Osman Duflay, a Mogadishu doctor, told the BBC's World Update programme that camp residents were facing "disaster".
"Especially the under-fives and the pregnant women, they're suffering from malnutrition and communicable disease like the measles, diarrhoea and pneumonia," he said.
Earlier this week Mark Bowden, the UN humanitarian affairs co-ordinator for Somalia, told the BBC that the country was close to famine.
"The next few months are critical," he said.
Last week Somalia's al-Shabab Islamist militia - which has been fighting the Mogadishu government - said it was lifting its ban on foreign aid agencies provided they did not show a "hidden agenda".
The drought is said to be the worst affecting by the Horn of Africa's in 60 years.
The International Committee of the Red Cross (ICRC) is reporting a dramatic rise in malnutrition rates even in the part of Somalia normally considered to be the breadbasket of the country.
Somalia, wracked by 20 years of conflict, is worst affected.
Some 3,000 people flee each day for neighbouring countries such as Ethiopia and Kenya which are struggling to cope.