More than 30,000 people have been displaced by recent clashes in Darfur between government troops and rebels, the head of United Nations humanitarian operations in Sudan said on Friday.
"NGOs and UN agencies are ready to deliver food, medicines, and blankets to people right now, and are trying to access the town of Muhajaria and villages between there and Shearia in order to do so," Toby Lanzer said in a statement.
"At least 30,000 people have fled from their homes in the Muhajaria and Shearia localities of South Darfur over the past days because of hostilities in the region," he said.
On Wednesday Sudanese troops took control of Muhajaria, two weeks after it was seized by rebels of the Justice and Equality Movement.
JEM chairman Khalil Ibrahim announced on Tuesday that he would withdraw his fighters from Muhajaria on condition that rival militiamen loyal to former rebel chief Mini Minnawi did not return to the town they lost last month.
At least 30 civilians were killed in the January clashes, "the most violent fighting since the signing of the Darfur peace deal" in mid-2006, an official with the joint UN-African Union peacekeeping force UNAMID said.
Most of those displaced by the fighting are still in the Muhajaria area.
"We need to have access in order to help" these people, said Orla Clinton, spokeswoman for the UN Office for the Coordination of Humanitarian Affairs (OCHA).
"As each day passes, people's need for assistance increases and the humanitarian imperative to reach them becomes more pressing," Lanzer said.
Humanitarian organisations evacuated their staff to Nyala some 80 kilometres (50 miles) west of Muhajaria because of the fighting.
The UN says about 300,000 people have been killed in Darfur since ethnic minority rebels took up arms against the Arab-dominated Khartoum government in 2003, complaining of discrimination.
Sudan says 10,000 people have died and denies charges that its soldiers and allied Janjaweed militiamen have committed war crimes and genocide in Darfur.