Sudanese authorities have ordered the Red Cross to suspend its activities, the organisation said, in the latest restriction to be placed on foreign aid workers in the country.
"We have received an official letter from the HAC [Humanitarian Aid Commission] informing us to suspend our activities with effect from today," Rafiullah Qureshi, spokesman for the International Committee of the Red Cross in Sudan [ICRC], told the AFP news agency on Saturday.
"Our activities are suspended."
He said the HAC cited "some technical issues" related to work which ICRC hoped to undertake this year in Sudan.
As a neutral intermediary, the Red Cross has facilitated the handover and repatriation of numerous prisoners held by armed groups in the country's war-torn Darfur region.
The agency has also provided health services, food aid, seeds, tools, hand pumps and other assistance that helped more than 1.5 million people in restive parts of the country last year, Qureshi said.
Although the ICRC's projects are suspended, its local and international staff, numbering about 700, will still go to their offices while discussions take place "in coming days" with the foreign ministry, HAC and other government agencies, he said.
The aim is "to resume our activities as soon as possible in favour of the victims of armed conflict." Qureshi said ICRC work in Sudan had previously been suspended in the 1990s.
The HAC could not immediately be reached for comment, but Sudanese officials have repeatedly expressed their wish to cooperate with international agencies.
However, access has been restricted to the states of South Kordofan and Blue Nile, where rebellions began more than two years ago and where the United Nations says more than one million people have been displaced or severely affected.
There has been no aid access to rebel-held areas of the two states since 2011.
In 2012, the HAC expelled seven international non-governmental organisations from impoverished eastern Sudan.
Also that year, Doctors Without Borders (MSF) said it had been forced to suspend medical activities in a part of North Darfur because of restrictions imposed on its work there.
In 2009, Sudan revoked the licences of 13 international aid groups working in Darfur shortly after the International Criminal Court issued a warrant against President Omar al-Bashir for alleged war crimes.