Oxfam Great Britain on Tuesday warned that 23 million people were facing severe hunger due to climate change-exacerbated drought in East Africa.
"This is the worst humanitarian crisis Oxfam has seen in East Africa for over ten years," Paul Smith Lomas, Oxfam's East Africa Director said in a statement.
"Failed and unpredictable rains are ever more regular across East Africa ... due to the growing influence of climate change."
Kenya, Ethiopia, Somalia and Uganda are the worst hit, while Sudan, Djibouti and Tanzania are also suffering ill effects.
Some 3.8 million people in Kenya are in need of emergency aid and deadly conflicts between pastoralists are increasing as communities fight for diminishing water supplies, Oxfam said.
In Somalia, which has also been hit by a bloody insurgency, another 3.8 million people - around half the population - are dependent on food aid.
Over 13 million Ethiopians are facing food shortages, Oxfam said.
The charity appealed for 9.5 million pounds ($15.1 million) to provide emergency food aid for 750,000 people.
Aid agencies operating in the region have suffered massive funding shortfalls this year as developed countries tighten their belts in face of the global economic crisis.