EXHAUSTED and emaciated Somalian refugees are pouring across the border into Ethiopia with horror stories.

I have spoken with some who walked for up to 25 days in the hope of getting food and water here in Dolo Odo, a border crossing in the Ogaden desert.

It's heart wrenching -- so many of the stories of these families are truly awful.

Mothers have had to leave behind their babies or weakest child in the hope of saving some of their other children.

It's unimaginable and heart breaking.

Today there are over 110,000 people who have struggled across the border to live in three camps here. Facilities are basic. People live huddled against the desert wind and sun in huts, sticks covered with plastic sheeting or cloth.

Already exhausted after a life-threatening journey to get here, many adults and children are severely malnourished.

It's a tent city and today an estimated 13,000 more people are waiting outside the camps, hoping to get in and access emergency aid.

Other refugee camps are planned and a camp for 60,000 people is under construction. In the meantime these unfortunate people are forced to sleep rough every night with little access to either food or water.

The sanitation facilities are basic and bad in some of the camps. The smell of human faeces is overwhelming.

GOAL is working with other agencies to improve the situation, but due to the harsh terrain it's not easy and we have to use special equipment to drill into the rocky soil to build latrines.

We have to ensure there are proper sanitation services otherwise there is the high risk of cholera -- and an outbreak in a tented city like this could be catastrophic.

This is the region's worst drought in more than half a century and Africa's first in almost thirty years. The conditions here in Dolo Odo are horrific.

The number of people at risk is truly frightening, even more so when they are put into context.

We know that nearly half the Somali population -- 3.7 million people are in crisis.

That's more than twice the population of Northern Ireland.

According to the World Food Programme, the drought is affecting another 3.2m people in Kenya, a further 3.2m in Ethiopia and approximately 120,000 in Djibouti. The total number of people facing starvation across the Horn of Africa is approximately 11m, or twice the total population of Ireland, both North and South.

I've been an aid worker for the past 11 years. I have seen the loss of life, destruction and suffering caused by massive disasters such as cyclones in Burma and Bangladesh; earthquakes in Indonesia and Haiti and of course, famine and cholera outbreaks across Africa.

In terms of famine and food crisis, this emergency in the Horn of Africa is one of the worst have ever experienced.

I spent a number of weeks in Niger last summer helping GOAL to respond to the food crisis there -- which was one of three emergencies in the world last year.

But this is far, far worse.

Dubliner Brian Casey is GOAL's Emergency Coordinator. He is currently based at refugee camps in Dolo Odo, a small town in south-east Ethiopia, where GOAL is providing assistance to the thousands of Somali refugees flocking across the border every day

- Dubliner Brian Casey in Ethiopia