Zamzam Camp, Sudan ? Every day, a peacekeeper truck pulls into this teeming camp carrying loads of water, and is greeted by long lines of refugees.

It’s not the troops’ job — but after the expulsion of many aid groups in Darfur, everyone is scrambling to fill the gaps in the safety net that keeps millions of refugees alive.

The expulsion ordered by the Sudanese government could not come at a worse time for Zamzam camp. Even before the order, aid groups were rushing to deal with an influx of refugees from the fighting — 37,000 in the past month, nearly doubling the camp’s size.

Now there are fewer medical clinics, fewer hands to help build shelters or distribute supplies. There are also fears of violence — borne out on Saturday when armed men looted a storehouse of the one of the expelled agencies, Oxfam, in another northern Darfur Al-Salam camp.

Khartoum’s expulsion of aid workers effectively decapitated the crucial humanitarian network for Darfurians, amid a 6-year-old conflict that has driven 2.7 million people from their homes and killed 300,000.

The order forced out 13 international aid groups and three Sudanese ones from Darfur and northern Sudan in retaliation for an international tribunal’s order for the arrest of Sudanese President Omar al-Bashir on charges of war crimes in Darfur.

The expelled groups made up 40 percent of the aid personnel and included some of the best organized and most experienced agencies dealing with the conflict.

Those aid workers who remain say they can fill the gaps in the short term, but warn of possible crisis within just a few months, with deteriorating health and outbreak of diseases — even violence, as desperation grows.

The Sudanese government dismisses the warnings are “premature,” insisting it can fill the gap working with U.N. agencies and the remaining groups. But many refugees deeply distrust government aid and suspect that Khartoum just wants to drive them out of the camps.

In Kalma camp, another overcrowded camp in southern Darfur, residents have barred government health workers or alternative foreign aid groups, despite an outbreak of meningitis. Journalists have also been denied access into the camp, which housed at least six of the expelled aid groups.

In Zamzam camp, where three groups were expelled, government Health Ministry officials are stepping up their role as well as local aid groups, such as the Sudanese Red Crescent.

At the compound of one of the expelled groups, the American CHF International, rolled up straw roofs are piled in a corner. Instead of being used to build shelters, they are being held by the government, and refugee women are collecting tree branches and straw to protect against the scorching sun.

“Al-Bashir came here and said no more aid groups,” said Mohamed Adam, a local guard assigned to watch the unused roofs. “Now the money has stopped … It is over,” he said, describing the government as “stubborn.”