Sudan has caused frustration among donor countries by ordering seven foreign aid agencies out of its impoverished eastern region, in what some fear is a sign of mounting hostility to outside assistance.

The government's Humanitarian Aid Commission (HAC), which conducted a rapid assessment of the operations of 14 international non-governmental organisations (INGOs) in the east, took the decision to expel seven of them late last month, arguing that some projects were badly managed, of poor quality and too costly.

The Sudan INGO Forum that represents them responded by saying that the organisations affected, which provide essential humanitarian aid such as healthcare for women and children, demining, water, sanitation and nutrition projects, served more than 600,000 people.

The region, which covers Kassala, Gedaref and Red Sea states, and where a fragile peace deal has held since 2006 after more than a decade of civil war, has "significantly worse" malnutrition levels than other parts of Sudan, one UN source said.

It also has the country's highest mortality rate for children under five.

"The consequence of the decision for the people of East Sudan, many of whom will be left without access to basic services, is therefore potentially grave," the INGO Forum said.

It is by no means an isolated decision.

Just the week before, Doctors Without Borders (MSF) said it had been forced to suspend lifesaving medical activities in a part of North Darfur due to restrictions imposed on its work there, leaving more than 100,000 people without vital healthcare.

MSF said the government "did not give us any clear reason" why medical shipments were prevented from reaching its project.

The NGOs ordered to suspend their operations in the east refused to comment, when contacted by AFP, some saying that to do so could jeopardise their activities elsewhere in Sudan.

But privately, humanitarian workers and Western diplomats express deep frustration, and worry that the government is acting with ever-more suspicion of, if not outright hostility towards foreign aid agencies in a country that can ill-afford to lose them.

"We are finding it more difficult to access the people who are most in need, wherever they may be located," said another UN source, speaking on condition of anonymity.

The latest decision appears to have been taken at a very high level in Khartoum, given the broad discrepancy between the HAC's findings and independent accounts of the NGOs' operations.

"It's my belief that these organisations have done nothing wrong... The evidence is that on the local level they were really liked," one diplomat told AFP.

"We are all afraid that this is the beginning of the cancellation of (humanitarian) projects in other parts of the country, such as Darfur. It's a negative trend," the diplomat added.

-- Sensitive region --

Khartoum has a history of expelling foreign aid agencies from sensitive areas, most notoriously when it revoked the licences of 13 INGOs working in Darfur in 2009 shortly after the International Criminal Court charged President Omar al-Bashir with war crimes.

INGOs and UN agencies were also ordered out of South Kordofan and Blue Nile when conflicts erupted between government forces and ethnic rebels last year.

They are still barred from accessing the embattled border states, despite reports of widespread food shortages and an estimated 500,000 people displaced from their homes or severely affected by the fighting.

The government frequently voices its determination to "Sudanise" the country's humanitarian operations, but diplomats from donor countries doubt whether the skills and expertise exist to deliver.

Some $3.5 billion were pledged for eastern Sudan at a donors conference in Kuwait in 2010 that was supposed to build on the 2006 peace deal.

But poverty remains endemic among the region's five million inhabitants and one diplomat said that the aid agency expulsions threatened to result in a "permanent loss of capacity" to deliver on humanitarian assistance.

Even diplomats are increasingly experiencing problems with their travel permits to the east, amid reports of growing discontent over the absence of any peace dividend for the ethnically divided region.

Hannah Reed, an aid worker with GOAL, described the severe living conditions in parts of Kassala state where the now-expelled Irish NGO worked, in a blog posted on the organisation's website last month.

"As I travel from Kassala town in eastern Sudan, to the rural areas in which GOAL works, there is nothing that would suggest it’s possible for people -- entire villages, in fact -- to survive," she wrote.