International aid agencies warned yesterday that Zimbabwe's humanitarian crisis was deepening, with a sharp rise in acute child malnutrition and a worsening cholera epidemic.

President Robert Mugabe's government has acknowledged the collapse of Zimbabwe's health system, but he also claimed earlier this month that the epidemic had been brought under control and that there was "no cholera" in the country.

Critics blame Mugabe's land reform policies for the collapse of Zimbabwe's farming sector and the ruin of what had been the region's breadbasket.

Zimbabweans are continuing to die of hunger and disease and acute child malnutrition in parts of the country had increased by almost two thirds compared with last year, said aid agency Save the Children in a report. Lynn Walker, the agency's Zimbabwe director, said "some children are wasting away from lack of food". The report said 18,000 tons of food were needed for January, with around five million people - half the population - in need of food aid.

In a separate report, the World Health Organization said that 1,518 people had died of cholera, with 26,497 cases recorded, since the start of the outbreak in August. The percentage of cholera patients dying from the disease rose to 5.7% last week, from 4% at the beginning of the month. Normally, only 1% of patients die in large outbreaks.

Paul Garwood, a WHO spokesman, said the outbreak was not under control and that neighbouring countries such as South Africa and Botswana, where the disease has also been reported, should increase their disease monitoring surveys and preparedness.