Niger has been hit by a double disaster as recent floods compound an existing food crisis, a UK aid agency warned.
Aid workers are struggling to help thousands of people affected by the floods which have hit many areas of West and Central Africa.
Oxfam says the situation is stretching resources to the limit as it also tries to respond to the food shortages.
The agency urged donors to help Niger face what it calls a second emergency.
Oxfam issued its warning as nearly eight million people, or half the population, are already facing hunger because of failed harvests.
Now more than 100,000 people have been left homeless after heavy rains washed away their homes earlier this month, according to the United Nations.
Floods have destroyed crops, and thousands of animals have drowned.
Oxfam warned that flooding is also hindering the delivery of aid in remote areas.
Floods will increase the risk of diseases, especially among young children suffering from acute malnutrition.
The World Food Programme recently acknowledged that it was forced to limit its food distribution to only 40% of those in need because of a funding shortfall.