Updated

About 250 people have been killed and 100,000 have lost their homes as catastrophic floods ravaged East Africa, aid workers said Friday as rains continued to pound the impoverished region.

Floods have hit Kenya, Somalia, Rwanda and Ethiopia, affecting more than 1.8 million people, according to the U.N. refugee agency. Weather experts warn that the punishing rains could continue through December in a region where a long drought has left the soil so dry it is unable to absorb the deluge.

Disease from poor sanitation is also taking its toll as submerged villages remain cut off and trucks laden with food and medicine are unable to reach survivors, according to the U.N. food agency.

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East Africa is one of the poorest regions in the world where most people live on less than $1 a day. It is home to more than 200 million people and regularly sees droughts and famine.

The U.N. is expected to launch an appeal Dec. 5 for an extra $17 million for flood victims. The organization already has received $10 million to help.

Some 41 people have been killed in Kenya and more than 700,000 people are affected, the Kenyan Red Cross said. The Health Ministry recently issued a cholera alert, the U.N added.

In neighboring Somalia, the death toll rose to 116 after 20 people died in the north of the country in an outbreak of diarrhea, the U.N. said. Some 15 people died in floods in Rwanda, officials said.

More than 80 people have died in Ethiopia, while 361,000 people have been affected in the southeast of the country.