In the deserts of Chad, a humanitarian crisis is unfolding. It's a disaster the world knows little about. Tens of thousands of refugees from the Darfur region in Sudan - fleeing a slaughter by the Sudanese Government and its militia allies - have trekked across the border. They've witnessed unspeakable crimes.
MOHAMMED SALEH, (Translation): They grabbed our children by the legs and threw them in the fire. If it was a boy, theyd grab him and throw him in the fire.
The United Nations is rushing to supply them with food and water. But in one of the world's most inhospitable regions, there's no guarantee the relief effort will succeed.
JEAN CHARLES DEI, UN WORLD FOOD PROGRAM: We're talking about 180,000 human beings being settled in camps where access will be not possible during the rainy season
If the operation falters, thousands may perish, including the very old and the very young.
JEAN CHARLES DEI: Today we have more than 100,000 people at risk of starvation.
The only way to judge the magnitude of the problem in Chad, involves a bone-jarring journey in scorching heat across hundreds of kilometres. Chad is dotted with refugee camps and other areas where refugees have gathered in large numbers.
We are heading for Touloum, the largest camp. This truck is carrying precious cargo there - food from the UN's World Food Program. Out of the desert, the camp appears quickly. The food is offloaded by local aid workers and given to those who've been registered.
The camp was designed for 6,000 refugees, but so many have fled from Darfur, it's now home to 18,000, and spreads across the surrounding dunes. The relief workers here - all but overwhelmed by a tide of hungry, thirsty people.
As Mohammed Saleh explains the daily food ration, in this extreme climate, lack of water is also a critical issue.
MOHAMMED SALEH, (Translation): Yes it is a problem, because with regard to water, for instance, we would estimate a certain amount per person per day. We were planning for 8000 people, but we ended up with 12,000 or 13,000. In just one week, between April 19 and 27, there was a spontaneous mass influx.
In fact, just trying to establish how many refugees there are, is a big headache. To make the camp function efficiently it's crucial that relief workers register all the refugees and hand out registration cards. But on this occasion no one seems to be around to take the cards, causing yet more confusion. And there's a bigger problem looming, the rainy season is about to begin.
MOHAMMED SALEH, (Translation): We hope that before the rains start, the large trucks reach us here, because during the rainy season the roads are cut off.
On the fringes of the camp, there's less chaos and space for quiet prayer. This is Tayedine Saleh and his son Assedeg. They're lucky to be alive, having survived an attack and a hazardous 16-day trek through the desert.
ASSEDEG: We are very poor people in Darfur and the government and soldiers of President Omar al Bashir and the Arab militia the Janjaweed, all attacked us in our village. All of our village was set alight and burned and they also killed the poor people in our village.
The Sudanese Government seems determined to drive out three marginalised ethnic groups.
TAYEDINE SALEH, (Translation): They killed the old men straight away, the old women too. They took newborn male babies and threw them in the fire. But before that, they killed their mothers. They left the female babies to cry and later took them away at night. So every day we were bombed from the air and attacked on the ground by Arab militias riding horses and camels, bought with government money. The government paid for their cars and fuel too, along with the horses. Camels and horses on the ground, government bombs from the air.
The next morning, there's a common ritual throughout the camp. The refugees want to know what's happening to relatives and friends in Darfur. After four years at university, Assedeg earned his living in Sudan teaching Arabic and computers.
ASSEDEG: Now my future is very, very bad future maybe because we left all our job and everything there in Darfur and until now, there's no green light for peace. Because of this, we are very worried for our future.
JEAN CHARLES DEI: It is almost now extremely impossible, I would say, to know exactly who is who along the border.
And it's not just the refugees worried about the future. Jean Charles Dei is the Deputy Director of the UN's World Food Program in Chad.
JEAN CHARLES DEI: What's the main problem we have now is that we need food right now - immediately. And this is also - if food comes late the only option we will have is by road over northern corridor or by air and the northern corridor will request a very high amount of money and by air is, no comment, you know how it will be - expensive.
We need to find a good fleet of truck then to go because private transport, they don't have reliable trucks. Total amount of money required is about, exactly US$38.5 million and we are fully sourced up to 53% so which means that we need the second half to be able to really confirm what will happen really.
Not enough food, money or reliable trucks - it's a bleak scenario, made worse because relief agencies have consistently underestimated the size of the problem. Their first plan was for 20,000 refugees - now there's at least 180,000 and more people cross the border each day.
JEAN CHARLES: The situation now is a bit desperate and we are continuing to struggle with several difficulties.
Nothing is easily resolved in Chad and we soon learn that trying to solve even small problems can be a very complicated process. 70km away are the people who designed the Touloum camp - relief workers from Norwegian Church Aid. They've got several truckloads of vital water-drilling equipment arriving at their compound. But now there's another water problem - someone's taken the bottled water belonging to the truckers' boss and he's not happy. His complaints bring the Norwegian team's work to a complete standstill.
GUARD, (Translation): Its impossible for someone from outside to steal my water. People working here must have helped themselves to the water. I asked him and he said it was you who
KATY: The guard apparently said we drank it, which is ridiculous.
Before the dispute is resolved, a far more serious problem arises. Someone has put a rocket-propelled grenade on the road outside. The explosive is on a truck route and it's also where children cross on donkeys.
TOR VALLA, NORWEGIAN CHURCH AID: We passed through four, five times this morning, because we were looking for water and suddenly I saw that, I say, "Oh, Jesus". Somebody has put this explosive on the road and then they remove it after three, four days and it turns up to be the same explosive we see somewhere else - it's a sort of game they're playing.
REPORTER: Dangerous game.
TOR VALLA: It's a dangerous one.
The Norwegians have been in dispute with local authorities over access to water - and wonder if the rocket reflects the continuing friction. It's a very sensitive issue and they're tight-lipped about it.
REPORTER: Who would do that?
RELIEF WORKER: I dont know, I can only guess and I dont want to guess.
Back in the compound, it seems the truck with the drilling equipment can't fit through the gate.
MAN, (Translation): If hes a good driver, he should make it. You must ask that driver there, I wont assume any responsibility. Someones got to be responsible for any damage. No damage, no problem.
KATY, (Translation): Cant they turn and come straight down this way?
But now the truck's inside, the mini-drama continues. Heavy cargo loaded in Europe by forklift has to be offloaded by hand, with sometimes, disastrous results.
RELIEF WORKER: The drilling equipment we have found it. They broke the case and we found it.
Amidst all the mishaps, I was surprised to learn that the water the Norweigans currently truck out to the Toulam camp - which is keeping people alive - has to be purchased at commercial rates.
TOR VALLA: Yes, the owner of the well, we have to pay him to get access to this water and that's a huge amount of money. So we are now struggling to develop holes in Touloum so we can start distributing water in a normal way, locally in Touloum instead of using trucks to transport water from Iriba towards Touloum.
REPORTER: How important is it that you get that drilling under way?
TOR VALLA: It's very important. It's only three or four weeks until the rainy season starts and we have to complete the bore holes in Touloum before the rainy season. So without this equipment, we might have to consider moving 70-90,000 people.
Moving an entire camp would be another logistical nightmare.
REPORTER: Katy, is relief work always this difficult?
KATY: No, I've worked in other conflicts where it hasn't been this stressful.
REPORTER: All this and it's only 9 o'clock?
KATY: Yes and it's Sunday morning as well.
Back on the road again. We're heading further north towards Bahai - to check reports that thousands of refugees have crossed the border. They're not in a camp - instead they've stopped - exhausted - in a dry riverbed, or wadi. It's hard to imagine, but the north seems even drier than where we've been. Soon the so-called road gives way to sand dunes. This is the route that cripples the ageing food trucks, making delivery to the refugees even more fraught. Midway through the journey - a flat tyre gives us a chance to meet the locals.
Because we're now close to the border with Sudan, we're on the lookout for refugees crossing over. And it's not long before we see small groups camped in the sand. And here's the wadi - the actual border. On the left is Sudan, the other side is Chad. It's the scene of past conflicts - and so dry that the donkey behind the children has died of thirst overnight.
It's a grim scene in the wadi. The families have escaped Sudan alive but lost all their possessions, and are living here with only the most basic support - some food and health care - from the UN and other agencies.
CENTRE FOR DISEASE CONTROL STAFFER: We're doing a nutrition and mortality survey in the camps here, in the Sudanese refugee camps.
REPORTER: To find out what?
STAFFER: Were looking at rates of malnutrition.
These staff from the Centre for Disease Control in the United States, later tell us that 27% of kids in the wadi under the age of five are malnourished.
The next morning we find Mariam Ahmed and her 80-year-old mother Sadiya and the survivors in their family making a meagre breakfast. Sadiya's son was killed by government soldiers and the Janjaweed militia.
MARIAM AHMED, (Translation): The planes came, then the Arabs and the government army, they burnt our village and we ran away. They killed the children. Some were left behind. We were scared, we were all scared. We dont know if the people left behind are alive or dead. On the way here, the Antonovs were bombing us, they were all around us.
SADIYA, (Translation): We were walking at night and we had to stop at dawn, all we do is cry and we cant sleep. My heart is going to break, my brain is gone. I lost my son, Im crying, crying. I dont know anything anymore. My cousin was left behind, others ran away, I dont know where they ended up.
There's as many as 10,000 refugees in Bahai now competing with the locals for water. And this is the only well in this part of the wadi. A few hundred metres away, at the small compound of the UN High Commissioner for Refugees, Axel Melinon is a man under great pressure. He's responsible for all the refugees in Bahai and about 7,000 more camped further north. He's on his way to the prison where a woman is locked up after allegedly hitting a refugee with an axe. The reason?
A dispute over water at the well.
AXEL MELINON, (Translation): I wanted to ask you to update me on the case.
GUARD, (Translation): Yes, one of them went to the hospital this morning. The doctor promised to produce a medical certificate in five days.
At the lock-up, the female prisoner is brought out.
GUARD, (Translation): It was about water, one of them went to the well, the one whos in hospital. As she was about to fill it, the one whos in hospital asked her Are you thick? No Im not And she started hitting her. Thats how it started.
After much discussion, who did what first remains in dispute. As UNHCR Protection Officer, Axel has to get to the bottom of the disputed claims and deal with the water crisis.
AXEL: The water in the wells is very dirty and there's not enough of water so more and more tensions between the local population and refugees and also between refugees themselves.
Melinon knows that the refugees are at risk in the wadi and he's trying to establish a new camp for them - or at least a transit camp. And now the rainy season is only a couple of weeks away.
AXEL: The wadi - all the area where the refugee are now will be flooded. So in a camp it's easier to control the security of people because we have direct access to them and also the health point of view its easier to control the rate of malnutrition and its easier to do all the vaccination.
For all the difficulties, Axel is one of only two UNHCR workers in Bahai. And he's clearly frustrated that his colleague will soon be leaving.
AXEL: The head of the office is on mission here so he is going to stay one month more, I hope I wont be alone, their going to send all the people.
We are heading back now, several hundred kilometres to the capital N'djamena. But we soon find another reminder of the crisis - these people huddled in 45-degree heat just outside a small town. It's like a scene from the Ethiopian famine of 1984, except no one is yet dying of starvation. The UN knows about their plight and wants to move them to a camp. With the UN thinly stretched in Chad and more refugees arriving each day, it's hard to imagine what the situation will be like in a few months time.
REPORTER: Can we say you are facing something of a disaster here?
JEAN CHARLES DEI: A disaster no, I think that we dont give up, were not giving up we are still fighting and we will continue fighting and we will also cope with the situation, but our coping mechanism will be as good as our international community supporting our effort.
As we head further south, the rainy season has begun and already it's changing the landscape. The dry wadis are filling. It's perhaps the cruellest irony that the water which renews this parched country, may halt the relief effort and cause even more suffering.