Shuffling in the dust among scrawny dogs and pot-bellied children, Kumke Lete wishes she could make it back across the border to Sudan's war-torn Blue Nile state to bring food to Doro refugee camp.
"For those that are able to go, they go. For people like me, I cannot go that distance," she said of the treacherous four-day round trip to the family farm, to bring enough grain to feed her seven children for two days.
Lete's family abandoned their home in Jindi a month ago when she said an Antonov plane "roared" over the village, unleashing its bombs on the camp.
"We are scared to go back, but... if we stay here we die of hunger," she said.
Lete's family is one of hundreds that walked for days to reach Doro, near the town of Bunj, about 40 kilometres (26 miles) from the border in South Sudan's Upper Nile state, where on average 1,000 people arrive every day.
With their meagre possessions dotted in bushes used for shelter, families say they fled with almost nothing or left essentials such as blankets and mosquitos nets along the way because they were so tired.
Tens of thousands have fled Sudan's Blue Nile state since the conflict erupted there in September between government forces and fighters aligned to the ex-southern rebels turned ruling party of newly independent South Sudan.
The United Nations refugee agency (UNHCR) has registered more than 21,000 refugees in Doro alone and says at least 5,000 more will arrive this week.
"We are expecting 30,000 people by the end of the year," said Assad Kadhum, emergency field coordinator for medical charity Medecins Sans Frontieres (MSF), which arrived last week to run a clinic in the camp.
MSF has planned two mobile clinics to treat patients fleeing Blue Nile, as well as 30 emergency latrines, before aid agencies arrive to tackle water and sanitation problems.
But the watering points meant for a community of around 4,000 people are already overstretched.
"People are waiting for five or six hours to collect water," Kadhum says.
Doro clinic is treating malaria and respiratory and muscle problems from people sleeping rough, skin diseases and diarrhoea from a lack of water and sanitation, and increasing malnutrition.
The UN World Food Programme (WFP) has distributed emergency food to more than 10,000 people since November 16, but it is battling logistical and supply problems.
"It's very difficult because the local places where we get food have been muddy and blocked," and air freight is limited because of several emergencies in the country, said Michelle Iseminger, Deputy Director for WFP South Sudan.
The organisation is also unable to access supplies stationed in a Sudanese transit camp for southern returnees across the border.
"There is food in Kosti, but it's caught up in the dispute between north and south," Iseminger said of the two nations that remain at loggerheads over key unresolved issues, including borders, and that accuse each other of funding rebel groups within their territories.
In addition to those fleeing to South Sudan, another 30,000 people are thought to have travelled to Ethiopian refugee camps from Kurmuk, the former rebel stronghold in Blue Nile state.
At Bunj clinic, Dr Evan Atar said he left Kurmuk on October 20 when the Sudanese army started shelling.
The town fell to the army on November 3, and the 60,000 people displaced within the state remain vulnerable to continuing conflict, a UN report said last month.
But Atar also fears for the health of the Blue Nile residents in Doro.
"The camp is really having a problem of the basic human needs," he says.
"Diarrhoea diseases are increasing... In the camp there is faecal matter everywhere and flies. It's just a matter of time. If we don't look after it now it will be a disaster."
Some families in Doro have already started to panic.
"We were given plastic sheets from UNHCR. When we saw the children crying from hunger, we took ours to the market to be able to buy some food," said Gadia Mani, who knows it will rain but had no choice but to trade each sheet for $9 of grain.
Mani pounded her fist against her palm when she talked of the Antonov hum over Borfa village that was bombed a month ago.
"I worry about food. I don't know how we're going to survive", she added, glancing at one of her five children who is eight months pregnant, and at the many grandchildren whose stomachs are also swelling.