South Sudan's bloody four-year civil war has inflicted a terrible toll on its people - with almost one million now forced to flee the world's newest country.

Every day, thousands continue to pour out of the country across the border into Uganda, many with harrowing stories of the brutal fighting they witnessed.

Africa Correspondent John Ray spoke to some of them at a huge refugee camp in Uganda. You may find their descriptions of violence distressing.

Emmanuel’s journey through hell began a little over a week ago, not long after the civil war that has raged for four years finally came to his village.

Some of his friends were already fighting – pressured, he says, into joining the rebel militia.

But Emmanuel, who is 18, dreams of finishing his education and becoming an engineer.

He chose to escape – a long and hard walk 20 miles south to the Ugandan border. It turned into a waking nightmare.

"Everywhere I walked I saw bones," he tells me, "And the terrible smell of bodies rotting. There were skeletons and skulls. Lying in the street. In every village that I passed.’"

I ask him about his friends he had left behind. His answer reveals the brutality of a conflict that has set tribe against tribe for control of South Sudan.

"One of my best friends was killed. They caught him and tied him to a tree.

"Then they beat him and shot into his chest. Finally, they set fire to his body."

Almost every one of the refugees we meet here has a horror story.

Joyce and her young baby fled the fighting, only to walk into an ambush.

She tells me her husband’s throat was cut in front her.

"The soldiers said ‘if you want to join him, no problem, we will lay you out next to him,'"she says.

We meet Joyce among the chaos of new arrivals at the Imvepi refugee camp.

Planned for 50,000 people, it now holds 130,000.

Joyce has no tent, no cooking pots, and when it rains, she and her baby get wet. ‘

"At least there are no bullets here," she says.

The number of refugees who have fled to Uganda is close to one million. Credit: ITV News

The number of South Sudanese refugees now sheltering in northern Uganda is about to top one million. Aid agencies are struggling to cope.

"People have escaped absolute horror in South Sudan and what they are faced with when they get here a further test of their resolve," Dorothy Sang of Oxfam tells me.

"We and other aid agencies are doing our best to respond, but we simply cannot cover everyone’s basic needs, such as food and water.

"This is Africa’s biggest refugee crisis and the international community is yet to respond with enough urgency."

Six hundred thousand refugees are children. Credit: ITV News

The rainy season has slowed slightly the flow of refugees.

But confounding all hope and expectation, it hasn’t stemmed the fighting.

At the border, one UN worker gives me this grim assessment.

"We are now seeing elderly people coming across. They thought they could sit out the war, but now their children are dead, they have no security so they must come.

"There are atrocities committed by both sides. The soldiers are not being paid; so what do they do? They kill, they loot, and they rape."

In a war with no winners, the biggest losers are South Sudan’s children – who make up 60% – 600,000 – of the refugees.

Most arrived without a mother or father. Many are entirely alone.

Sixteen-year-old Grace is pregnant after being raped by men who pretended to help her. Credit: ITV News

Grace is 16. Her childhood ended on the road to Uganda.

Her mother was taken by soldiers at a checkpoint along the way, her older brother murdered the next day.

A few miles further on and she met a group of armed men who offered to escort her safely to the border.

Instead they took her into the bush and raped her. Now she is pregnant.

"If the child is a boy, he will be my brother. If it is a girl, she will be my little sister,’" Grace tells me in her quiet voice.

"There were four men. The biggest man, raped me. He slapped me. I screamed but there was no one to help."

If war continues, the children of South Sudan will become known as the 'lost generation'. Credit: ITV News

At the largest of the camps, Bidi Bidi, Richard Duuki, of World Vision is working with the most damaged and vulnerable children. There are tens of thousands of them.

"It is a generation at risk. If we do not make a concerted effort to meet their needs, we will call it a lost generation."

These are children who have grown up with nothing but war and have learnt nothing but hate.

And yet, if South Sudan is to have a future, it lies with among the under-funded schools and care centres in the camps.

"A child has been raped, a child has seen his father murdered in front of him," says Richard.

"We must try to make them realise this not the end of the story. There has to be a point of hope."

Among all the shortages in the camps, hope is the one commodity most urgently needed.