DZAIPI - In the steaming heat of Uganda, just south of the border with South Sudan, long lines of tents crowd the Dzaipi refugee camp where tens of thousands have fled fighting in their war-torn nation.
Dzaipi was designed for 400 people, but at one point the flood of South Sudanese refugees swelled to some 35,000 as Uganda bears the brunt of the massive exodus from the world's youngest nation.
Mabior David, aged 15, fled the fighting with his sister and arrived in the camp two weeks ago, leaving the rest of his family behind.
"They wanted us to come to Uganda," he said simply. "They have remained there to fight."
In the overcrowded camp, refugees find space where they can, in simple shelters or beneath the shade of a tree.
Snaking lines of women and children queue patiently in the baking sun to fill containers of water. Elsewhere cooks prepare food in giant pots, as children wait impatiently for their ration.
But in this line, there is not enough, and the children cry for more food.
As clashes continue despite a recent ceasefire deal, over a thousand people are leaving behind their homeland -- born with such optimism less than three years ago -- for Uganda every day, aid agencies say.
"We are facing challenges in almost every sector," said Lucy Beck, of the UN refugee agency, UNHCR, adding that the provision of clean water was a key concern.
Over 112,000 refugees have fled South Sudan since fighting broke out on December 15, including over 60,000 southwards to Uganda, as well as to Kenya, Ethiopia and north to Sudan, according to the United Nations.
Refugees in Dzaipi are now being slowly moved to a larger space nearby to relieve the massive overcrowding, with the camp now hosting some 16,000 people.
"They get plots of land and are given basic items and food from the World Food Programme," Beck added.
Up to 10,000 people are believed to have been killed in the fighting pitting forces loyal to President Salva Kiir against a loose coalition of army defectors and ethnic militia nominally headed by his arch-rival Riek Machar, a seasoned guerrilla fighter.
The fighting has been marked by atrocities on both sides with some 700,000 people forced from their homes in the impoverished nation, according to the United Nations.
"More than 1,000 South Sudanese refugees, mostly women and children, arrive every day," across the border into northern Uganda, the aid agency Oxfam said in a statement.
"The sheer numbers that we are seeing today are cause for genuine concern," Oxfam's director in Uganda Peter Kamalingin said. "We need to do everything we can to redouble efforts to help refugees."
Medical aid agency Doctors Without Borders (Medecins Sans Frontieres, MSF) are also on the ground.
"We are treating serious cases of malaria, diarrhoea, and respiratory tract infections," said MSF's Fredericke Dumont, supporting the thousands squeezed into Dzaipi.
"There are women suffering complications during pregnancy, and some cases of malnutrition."
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South Sudan refugees overwhelm Uganda aid workers