The little hospital built from plastic sheeting and wooden poles is not much to look at. Yet it serves 20,000 of Darfur’s suffering people, offering life-saving medical care to families who fled their homes with nothing.

Yesterday it was closed. Its patients were sent home and doctors and nurses told not to turn up for work. The Sudanese Government, having bombed more than two million people into the camps, is expelling aid workers in retaliation against a world that wants to arrest its President.

Aid officials warn that a humanitarian emergency is in danger of becoming a disaster. The move has put the supply of food to 1.1 million people in doubt, as the UN’s World Food Programme scrambles to find lorries to deliver sacks of grain. It had been using four of the expelled charities to get food to people in need. Outside the hospital – run by the International Rescue Committee until it was ordered out – a mother brushed flies from the face of her daughter. “My baby is sick,” Fatima Abdulrahmen said. “She has a fever and I brought her here and now I don’t know what to do. Who will help me now?”

The people who should be helping – the staff of 13 international charities including Oxfam, Médicins sans Frontières and Care – were boarding flights to the capital, Khartoum.

Government officials began making telephone calls on Wednesday, seconds after the International Criminal Court (ICC) announced that it had issued a warrant for the arrest of President al-Bashir. They told aid agencies that their licences to operate were being revoked for passing information to ICC investigators.

Mr al-Bashir is wanted on two charges of war crimes and five of crimes against humanity in Darfur. The United Nations has estimated that 300,000 people have died in six years of fighting, many at the hands of the Janjawid – Arab militias armed by the Government and deployed as a counter-insurgence force.

The Government called mobs on to the streets of the capital yesterday in an angry show of support. More than 10,000 people, many screaming furiously, poured in to Martyrs Square to cheer on their President. Some burnt Israeli flags and effigies of Luis Moreno Ocampo, the ICC’s chief prosecutor. Mr al-Bashir, who seized power in a coup in 1989, turned his ire on the US and Europe. “We are telling the colonialists we are not succumbing. We are not submitting. We will not kneel. We are targeted because we refuse to submit,” he told the crowd.

The African Union said yesterday that it was sending a delegation to the UN to urge the Security Council to defer the arrest warrant, fearing that it could provoke more turmoil and wreck the fragile North-South peace process in Sudan. The Sudanese representative in the African Union called on African states to withdraw from the ICC in protest.

Human rights campaigners accused Sudan of holding the people of Darfur hostage. “Millions of lives are at stake and this is no time to play political games,” Tawanda Hondora, deputy director of Amnesty International’s Africa Programme, said. “These aid agencies provide the bulk of the humanitarian aid required by more than two million vulnerable people.”

In El Fasher, capital of North Darfur, government officials began the process of seizing millions of pounds in assets belonging to the charities. Men with dark glasses and clipboards arrived at the Oxfam office to begin itemising equipment. They left with laptops, desktop computers and satellite phones, choking off communication. There was a similar scene at the French agency Action Contre La Faim. “We are due to start distributing food to the camps in a fortnight,” one worker said. “Who else is going to do this and stop people starving? Words cannot describe what is happening.”

Charities reported that their bank accounts were being frozen. Doctors with Médicins sans Frontières were trying to contain two deadly outbreaks of meningitis before being expelled. Their clinics have closed.

In Abu Shouk, home to about 50,000 people, men dressed in dusty jalabayas were hammering at a water pump. This should be the work of water and sanitation engineers from Oxfam. “We don’t know how to fix it,” said one man wielding a foot-long spanner, “but we are thirsty.”

In neighbouring Al Salaam the umdas – or chiefs – gathered to discuss the news. Adam Mahmoud, the chief umda, gestured one way and then the next as he pointed out the International Rescue Committee hospital, latrines dug by Oxfam, feeding centres and camp administrative offices, all run by foreign charities. All are closed.

“If these organisations leave then there is no doubt that we will all suffer again,” he said. “It will be a disaster.”