Sudan has ordered the expulsion of two senior international aid workers it claims have made political statements about the crisis in Darfur.
Sudan said the agencies work "against the direction of society"
The country directors of British charities Oxfam and Save the Children were told to leave within 48 hours.
The Sudanese government accused both organisations of prolonging the conflict rather than helping it.
Save the Children last week withdrew a team of aid workers amid fighting in the North Darfur town of Tawilla.
Sudan's Humanitarian Affairs Commission claimed the British-based organisations had broken laws on non-intervention in Sudan's political, ethnic or sectarian issues.
'Support for outlaws'
Save the Children said that field workers were forced to flee from Tawilla when government warplanes bombed a site close to a feeding centre run by the organisation.
Oxfam has been working throughout northern Sudan for 20 years and Save the Children is one of the largest food distributors in Darfur.
It provides food to more than 300,000 of around 1.5 million refugees in the troubled region.
The expulsion was ordered in a letter signed by Abdel Khaliq Al -Hussein, acting commissioner for humanitarian affairs.
In a statement published by the official Sudan News Agency, Save the Children and Oxfam were criticised for "sending signals of support to the outlaws and rebels for
continuation of the war in Darfur".
An Oxfam spokesman confirmed that the organisation had received an official letter from the Sudanese government but was seeking further clarification on the issue, reports said.
The expulsions came one day after the governor of North Darfur lifted a state of emergency and called on agencies to resume their work in the region.
But UN World Food Programme officials said the move was not enough and denounced continuing violations of a recently-signed ceasefire deal.