KHARTOUM: Aid delivery is in jeopardy for an estimated 100,000 people affected by violence in Sudan's Darfur region unless authorities grant better access, the United Nations warned on Thursday.

One humanitarian agency has said the number of displaced people is the largest in recent years in Darfur, where a decade of civil war has been compounded by inter-Arab violence, banditry and tribal fighting.

But the true extent of the problem is unclear because UN workers have had only limited access to the affected area of Jebel Amir, the UN humanitarian agency OCHA said in its weekly bulletin.

Foreign aid workers, diplomats and journalists routinely face restrictions on their movement in Sudan's far west.

"The UN has informed the Sudanese authorities that it will not be able to continue providing food and other relief unless the relevant UN officials in North Darfur are permitted to travel to the area to register those in need of assistance and to carry out a comprehensive assessment," OCHA said.