A BBC team has arrived at a transit centre in Renk in South Sudan, where staff from UN agencies say they lack the required resources to help those fleeing across the border from Sudan.
They told the BBC have had to set up operations almost from scratch, though basic services like water, food and tarpaulin tents are being provided.
Renk is close to the border with Sudan, where more than 4,000 people are living after fleeing the conflict that erupted nearly three weeks ago.
BBCCopyright: BBC
Around 30,000 people in total have come to South Sudan from Sudan in that time – most are South Sudanese, but some are Sudanese and other nationals.
Many are staying with family or local communities, others have made it to the capital, Juba.
Here in Renk groups of families and friends, some with toddlers, are living out in the open in makeshift tents while others are camping out in abandoned buildings at a former university campus.
South Sudan has already been impacted by years of conflict, and its broken economy is struggling to provide support for those coming across the border.
Trade with Sudan has already been cut because of the conflict as government ministers warn of long-term impacts should the fighting continue.