In the eyes of aid workers it is not the right moment for a change of guard. But despite a looming humanitarian crisis and growing insecurity fears, the EU mission in Chad expires this weekend. The UN takes over operations.

Women in bright robes clamour for sacks of grain and canisters of oil under a beating sun. A flurry of activity has interrupted the customary lull of the midday heat, triggered by the arrival of aid workers with trucks of food to the Am'nabak refugee camp in eastern Chad.

Home to around 16,000 refugees, this is one of the smaller camps set up in 2004 to provide a shelter for families fleeing the bloodshed in Darfur, just across the Sudanese border to the east.

It is these refugees and tens of thousands of others like them, as well as aid workers, that the EU had been mandated to protect in its largest-ever African mission.

EUFOR's 2,700 multinational soldiers, including 60 Dutch marines, have had their work cut out over the past year: a complex network of rebels and bandits criss-cross the Chadian desert in pick-up trucks, brandishing machine guns and spreading fear.

Soldiers regularly camp out in the desert in order to carry out night patrols around refugee camps. Nights are the most dangerous time so they are allowed to remove their bullet-proof vests and full combat gear only during their short hours of sleep.

"We are always on standby," says Major Darek Kudlewski as he prepares for the patrol. "There are lots of groups with guns and often we can't even tell them apart. There is always a very tense first minute when we come face to face with rebels, wondering if they will fire or not. It's very stressful. But still, we feel we are making a difference. Our job here matters. "

Major Kudlewski is part of the 400-strong Polish contingent in eastern Chad, where the mission has booked some big successes: there have been no major violent incidents around any refugee camps - home to over 120,000 Sudanese - since it reached full operational capacity and the locals say they feel safer when they are around.