A lack of resources for emergency relief efforts in Ethiopia threatens to cut off food aid delivery to the most vulnerable people in the coming days, the United Nations humanitarian arm warned today.

"All food aid pipelines to groups of needy people in the country could break in September," the UN Office for the Coordination of Humanitarian Affairs (OCHA) said in an update on the situation in the Horn of Africa nation.

Poor rains in eastern Africa this year has produced crises in the areas of food, nutrition, water and disease among others, leaving some 24 million people in need of aid - up from 17 million last year - across the region, in Djibouti, Eritrea, Kenya, Somalia and parts of Uganda, as well as Ethiopia.

OCHA noted that currently food aid distributions planned between September and December face a deficit of some 56,789 metric tons valued at $37.1 million.

In addition, a joint mission, consisting of various UN agencies and the Ministry of Health, is in the Amhara region to assess an outbreak of acute watery diarrhoea, which has struck a number of regions, to ensure adequate measures are in place to prevent infections gathering pace in schools and religious and traditional festivals, among other areas.

The World Health Organization (WHO) reported that major gaps in the ongoing response to the outbreak include shortages of Case Treatment Centre materials, funds for running the centres, inadequate protection of water sources and poor hygiene practices.