Six agencies operating in the war torn area issued a statement Friday saying they had to recall 250 workers due to military activity, banditry and violence, the BBC reports.
According to the agencies, the workers were serving 488,000 refugees who have fled the continuing war between rebels and government-backed militias.
"With new displacements and attacks, the presence of aid agencies is more important than ever," says Paul Smith-Lomas, regional director of Oxfam, "yet every day brings one huge blow after another to aid efforts."
Violence has intensified in Darfur despite the presence of some 7,000 African Union peacekeepers.
Sudan has rejected plans for the United Nations to take control and increase the number of peacekeepers to 20,000.