Increasing attacks by armed militias are threatening the work of humanitarian agencies in West Darfur.

The African Union's peacekeeping mission in Darfur was targeted by militants over the weekend, when the AU treasurer was attacked metres away from the gates of the organization's base.

A third of Darfur's population has been displaced by war, leaving many reliant on aid organizations such as the Canadian-funded Fellowship for African Relief.

Andrew Yunda heads a food security program for the NGO, delivering assistance in El Geneina, one of the most hostile regions in Darfur close to the border with Chad.

"We help them with seeds and tools … to cultivate food for their own … within secure lands," said Yunda.

Cross-border raids by Chadian and Sudanese rebels have made field work extremely dangerous, however, said Yunda. "We are now unable to go using our own vehicles to our field location.… It's changing from bad to worse."

Millions in Darfur are living in squalid camps like the one in El Geneina, leading many in the camp to walk 20 kilometres and cross the border into Chad.

But Yunda said this was no solution. "It's like jumping from a frying pan into fire. You think it's better, but when you go to the other side you get it worse."

Millions of people are struggling to survive in the increasingly violent climate, which threatens the delivery of humanitarian aid that helps them survive.