An international aid agency has closed some of its bases in the Democratic Republic of Congo because it is too dangerous for its staff to work.
Some 60,000 people have been killed in ethnic clashes in Ituri
More than 100,000 people will be left without access to medical treatment, says Medecins Sans Frontieres (MSF).
It will continue working in the north-eastern town of Bunia but not in the surrounding countryside.
Armed groups continue to roam much of north-eastern DR Congo despite the presence of UN peacekeepers.
Some 60,000 people have been killed in years of ethnic clashes in Ituri.
Two MSF staff were kidnapped in June, and held for 10 days before being released.
MSF said the population in the area have been left to fend for themselves, leaving them at the mercy of what "the limitless violence" of armed groups.
The announcement came as MSF released a new report: Nothing New in Ituri: The Violence Continues.
It said that more than 90% of the 795 families interviewed said they had had at least one member kidnapped during attacks on their villages.
The men were used to carry looted goods and weapons, while women became cooks and sex slaves, the report said.
"After looting and burning the huts in that village, the armed men gathered up all the girls and took them to be their wives far away into the forest," a 14-year-old girl told MSF.
Some 15,000 UN troops are in DR Congo following an agreement to end a five-year civil war.
They have recently launched raids on Rwandan Hutu rebels based in eastern DR Congo but there are many other militias in the region.
In January, MSF - Holland closed a base in the neighbouring North Kivu province after it was attacked by armed men who stole money, equipment and a car.