In war-torn South Sudan at least nine people have died in a cholera outbreak, says the World Health Organization.
"There have been nine deaths and 138 cases so far," WHO spokesman Tarik Jasarevic told AFP in Geneva.
"The epidemic is intensifying and more cases are expected," he said.
The outbreak of the highly contagious disease has raised the spectre of an even broader spread, given that 1.3 million South Sudanese have been forced from their homes by five months of fighting.
Huge numbers of people across the country are surviving without proper shelter, clean water or toilets.
Over 79,000 civilians are sheltering in hugely overcrowded United Nations peacekeeping bases, including over 32,000 civilians crammed into UN camps in the capital alone.
Heavy rains are sweeping the impoverished country, hampering aid efforts and potentially exacerbating the spread of the disease.
Children are at particular risk from cholera.
"The severity of the cholera outbreak is just one manifestation of a country failing its children," said Jonathan Veitch, who steers South Sudan aid operations for UN children's agency UNICEF.
"Cholera puts ever more strain on the most vulnerable, whose health is already compromised by a nutritional crisis," he said in a statement.
Cholera is transmitted through drinking water or eating food contaminated with faeces or dirty hands.
After a short incubation period of two to five days, the disease causes severe diarrhoea, draining the body of its water. The dramatic loss of fluid is often fatal.
Aid organisations have warned of a growing humanitarian crisis in the young nation, including the risk of famine if rebel and government forces continue to fight.