AMBELA - Bang Chuol was studying to become a geographer in South Sudan when soldiers arrived at his home and gunned down his entire family, forcing him to flee in an instant.
"I saw them die myself," the demure 20-year-old said, speaking in a crowded refugee camp in Ethiopia.
"People were killed indiscriminately. I was living with my family, and I was very happy living with them, but they were killed one by one," he said of losing his mother, brother, aunt and nephew in the swift, bloody slaughter.
He is one of more than a million people who have fled their homes in the 100 days since the beginning of the conflict in South Sudan, creating a massive humanitarian crisis in the region.
Many of those who fled were, like Chuol, seeking to rebuild the world's newest nation after decades of war with Sudan that finally led to independence from the north in 2011.
For Chuol, education was the top priority. Now, his sole focus is surviving in the underserved refugee camp, where more than 80,000 people have sought safety in only three months.
"Life for us refugees is difficult, supplies are not enough, but on top of that I just want to go to school, back to where I studied," said the slight young man.
Fighting broke out on December 15 between government soldiers loyal to President Salva Kiir and rebels loosely allied to his sacked deputy Riek Machar. The violence has escalated into full-scale fighting across the country and has already killed thousands of people.
Aid workers and rights groups have been sounding the alarm over the recruitment of child soldiers, especially with so few young men crossing into the refugee camps.
"We have now confirmation that child recruitment into the military is going on in South Sudan, so that's absolutely a risk," said Peter Salama, head of the United Nations children's agency in Ethiopia.
Some refugees are returning to Ethiopia for a second time, having fled for safety and food during the two-decade war with Sudan.
Bol Gatkuoth Bithaw, 33, returned to South Sudan in 2007 after 10 years in Ethiopian refugee camps, with ambitious plans to reconstruct his country, one the world's poorest nations.
"I was very happy because it was my first time to smell peace. My hope was to build the country," he said, sitting on a pile of logs near a food station where scores of women waited to receive grain sacks.
"Now the hope is degraded," said the second-time refugee, who had been working as a disarmament officer for former child soldiers in the northern town of Malakal before he was forced to leave last month.
- A new tragedy -
Bithaw spent weeks walking to the Ethiopian border with his wife and two-year-old son, avoiding dead bodies and foraging wild fruit and edible leaves before finally reaching safety.
Aid agencies are struggling to serve the rapidly growing refugee population -- with up to 1,000 new arrivals into Ethiopia daily -- and the United Nations said $654 million (474 million euros) is required to respond to the crisis.
Malnutrition has reached critical rates, with about 30 percent of the population suffering, and the threat of diseases such as measles, malaria and cholera is looming.
"We have a combination of malnutrition and overcrowding, and always the risk is to have on top of that infectious disease outbreak, which is what kills refugees," said Salama.
Martha Nyaluak, 35, is struggling to care for her six children, including her youngest, who has severe diarrhoea.
This is her second time in Ethiopia as a refugee, after returning to South Sudan's oil-rich Upper Nile state in 2007 to start a new life at home.
"I was happy because my children were enjoying good schooling, proper healthcare, and other development like roads and bridges," she said.
The piecemeal gains made in the young nation since independence are now shattered, and Nyaluak does not know when or if she will return.
"I feel bad now because in place of development is now war," she said.
Peace talks between government and rebels in luxury hotels in Addis Ababa have made little, if any, progress, and both parties continue to violate a ceasefire agreement signed in January.
Humanitarian groups are appealing for urgent peace, and have called both sides back to the negotiating table after the latest round talks was adjourned until the end of this month.
The head of the UN refugee agency, Antonio Guterres, this week warned of the situation becoming "a true calamity".
"This is a tragedy I was hoping I would not see again," he said, speaking at the border crossing between South Sudan and Ethiopia, where hundreds of refugees waited to be resettled and fed.
"Peace is an absolute must, and the international community must come together to make sure that the parties make peace," he said.
For now, some cling on to shreds of hope the war will end before it is too late, even as fighting rages on in the country.
"I hope it's not too late for us to come together because this is an experience, people learn from their mistakes," Bithaw said.