GENEVA, Aug 6 (Reuters) - Sudan has ejected 20 United Nations staff working to help hundreds of thousands of people who have been uprooted by war in Darfur region, the U.N. refugee agency UNHCR said on Tuesday.
Of UNHCR's 37 international staff in Darfur, 20 have not had their work permits renewed, UNHCR spokeswoman Melissa Fleming told a regular U.N. briefing in Geneva.
"Most of them were asked to leave at short notice in July. As a result we've been unable to effectively undertake our work there," she said.
UNHCR helps to protect, shelter and return displaced people, who number about 2 million in Darfur, including 1.2 million in camps. There have been almost 300,000 displaced this year, including 100,000 in the north, UNHCR said.
UNHCR has not had any explanation for the expulsion of its staff members, all of whom were based at El Fasher in north Darfur, which Fleming described as "a major operational hub".
She did not provide details about them but said their expulsion did not appear to be related to their nationalities.
The decision not to renew the permits was thought to have been taken by the government in Khartoum, not by local officials, Fleming said.
Other U.N. agencies, such as UNICEF and the World Food Programme, have not had any problem with renewing work permits.
In Washington, State Department spokeswoman Jen Psaki said Sudan should immediately renew the work permits of the UNHCR staff.
She said the government's actions raised serious concerns and questions about the viability of a 2011 peace agreement between the Sudanese authorities and rebels groups.
"We call on the Government of Sudan to allow UNHCR and all humanitarian actors unfettered humanitarian access to all parts of Darfur to protect and to assist the victims of the conflict and to support the implementation of the peace agreements," Psaki said in a statement.
Years of international peace efforts have failed to end conflict in the westerly region of Darfur, where mainly African tribes took up arms in 2003 against Sudan's Arab-led government, which they accuse of discriminating against them.
Violence is down from its peak in 2004-05, but has picked up again this year as Arab tribes, many of which were armed by government early in the conflict, are fighting among themselves over resources and land.
Fleming said the humanitarian situation was "critical, unstable, volatile, both for the people who have been displaced for years on end but also for many newly displaced people".
In April, about 50,000 Sudanese fled into Chad after a bout of conflict in Darfur. But the displacement into Chad has "pretty much stopped" very recently, Fleming said. (Reporting by Tom Miles; Editing by Michael Roddy and Mohammad Zargham)