Nairobi, Dec 20 (IANS): The UN humanitarian agency has warned that conditions are set to worsen for millions of hungry people across Eastern Africa as the El Nino weather phenomenon continues.

The UN Office for Coordination of Humanitarian Affairs (OCHA) said an estimated 18.5 million people are food insecure as of December, a situation exacerbated by the effects of El Nino, Xinhua reported.

"The food security situation is of great concern, with an increase of 64 percent increase in the number of food insecure people between August and December," OCHA said in its latest humanitarian report received on Saturday.

According to the UN, the impact of the El Nino climatic event since May has manifested itself primarily in persistent drought conditions, most acutely in parts of Ethiopia and Sudan, and drier than average conditions in parts of Eritrea, Greater Upper Nile region of South Sudan, parts of northern Uganda and parts of Somaliland and Puntland, in Somalia.

OCHA said enhanced El Nino-related rains have increased the risk of flooding along the main river systems in Ethiopia, Kenya, Somalia and Uganda.

"Nearly 100 people have died as a result of flood related incidents in Kenya and more than 300,000 people displaced in the four countries," the UN said.

It noted that the displacement is however significantly lower than expected and the enhanced rainfall has favoured arid and semi-arid areas with good pasture, crop development and replenished some water sources.

The Eastern Africa region as well as several other regions, are experiencing abnormal rainfall patterns, since the El Nino rains are expected to continue through the first quarter of 2016.

Though the above-average October to December rains will be beneficial for both agricultural and pastoral production in the region, there is a risk of river and lakeshore flooding, as well as flash floods, aggravating an already bad situation.

While respective national governments and humanitarian partners are responding to the El Nino related needs, significant resource gaps have been reported in all critical sectors.

"Governments and humanitarian partners have scaled-up response activities, working with local authorities and community leadership to strengthen local response capacity," it said.

The regional Food Security and Nutrition Working Group (FSNWG) has called for further scaling-up of life-saving and livelihood support activities (especially for pastoralist) until mid-2016 when the next season's crop harvests and animal products are expected.

Humanitarian requirements in the Horn and Great Lakes region totalled $5.7 billion in 2015, and are only 49 percent funded at year-end.

"Increased funding is required to address both increasing displacement and to respond to the drought and flood impact of El Nino," OCHA said.

"Disaster risk reduction and preparedness activities should continue beyond the El Nino period. The region is prone to floods and drought even outside El Nino years. Development funding should be programmed for early recovery as a strong El Nino is historically often followed by a La Nina," the UN said.