The Sudanese government yesterday began ordering aid agencies to leave the country, leaving millions of people without aid in Darfur.
Officials began telephoning charities at 16:05 local time, seconds after the International Criminal Court announced it had issued a warrant for the arrest of Omar al-Bashir.
They were told their registration in the country was cancelled with immediate effect.
The charities expelled include Oxfam, Care International and Action Contre la Faim - all seen as "big hitters".
Staff will begin leaving the country today(Thursday).
"We didn't know how the government was going to react," said a Western diplomatic source. "This is one of our worst-case scenarios."
Aid organisations have long had a tricky relationship with Khartoum, which regularly denies visas for staff or closes off areas where it is conducting military operations.
However, the humanitarian operation was one of the few successes in Darfur, helping care for more than 4m people.
About two and a half million people live in camps after being forced from their homes by fighting.
Agencies were concerned that they could face a backlash from the government, fears that now appear well-founded.
Penny Lawrence, Oxfam's International Director, said the charity would appeal the decision.
"If Oxfam's registration is revoked, it will affect more than 600,000 Sudanese people whom we provide with vital humanitarian and development aid, including clean water and sanitation on a daily basis. 400,000 of them are affected by the ongoing conflict in Darfur - where people continue to flee from violence and the humanitarian needs remain enormous. It will also affect another 200,000 poor people in the east of the country and Khartoum state."
An aid official said the move would have a catastrophic impact in areas where charities were distributing food and medicine.
"The largest aid operation in the world hinges on the NGOs. Asking 10 of them to leave will seriously compromise its effectiveness."
Yesterday the Times revealed that six agencies had been asked to leave key sites in Darfur.
Today they were ordered out of the country altogether.
The other agencies are CHF, Solidarites, MSF-Holland, Save the Children, Norwegian Refugee Council, The International Rescue Committee.
Khartoum has expelled numerous aid workers in the past and maintained a steady level of harassment.
Jewish staff have been accused of being Mossad agents and several charities have been smeared in the government-controlled press, accused of using out-of-date medicines.
This is cross-posted from The Frontline Club