Food shortages are already hitting hard thousands of refugees in Yida and growing malnutrition may trigger violence at the camp.
The alarm was raised by humanitarian workers who spoke off-record to the Sudan Catholic Radio Network at the camp in Unity State.
Yida is home to more than 71 thousand refugees from Nuba Mountains since August 2011.
The Government ordered UNHCR, the UN refugees’ agency, to stop registering newcomers at Yida on April 4.
The Government and UNHCR consider Yida a provisional camp and too close to the border to be safe.
They want to relocate the refugees to Ajuong, further South East.
Unregistered refugees are not entitled to ration cards and do not receive food and other aid.
One medic said some 3,000 unregistered refugees are surviving on food shared from others and there are already pockets of malnutrition in the camp.
He commented that hungry refugees know where food is stored in the camp and may try to get it through violent means.
UNHCR has enough food for 100 thousand people until the end of the year stored in some 30 rubber halls by the airstrip in the camp.
Almost 1,200 refugees are already in Ajuong but more than half are 18 to 25 years old males who moved to dig pit latrines and do other paid works.
Many Yida refugees said that they will not move to Ajuong because it is too far from Nuba Mountains.
Report by Sudan Catholic Radio Network
Photo: Refugees in Yida Camp preparing to board a truck to return to the Nuba Mountains after opting not to accept transfer to Ajuang Camp, 30 March 2013 (Radio Tamazuj)