About 80,000 people have been displaced by fighting in the north-east of the Democratic Republic of Congo this year, according to UN officials.
By Robert Walker
BBC News, Kigali
They say nearly half have fled Ituri region in the last four days.
Ituri is highly unstable, despite the presence of UN peacekeepers and a peace agreement designed to end Congo's five-year civil war.
The UN has warned of a humanitarian crisis in the region.
Officials from the organisation say many of the newly displaced have travelled long distances on foot, taking with them only what they can carry.
UN peacekeepers have deployed in three new towns in recent weeks to try to protect civilians from attack.
But as they have done so, more people have arrived from surrounding areas seeking their protection.
Aid agencies are providing food, water and medical care in the areas safe enough to access.
The rebels were supposed to join the national army
The displacement follows renewed clashes between militias from the Hema and Lendu ethnic groups.
These groups have continued to fight for control over Ituri's natural resources, despite the official end of Congo's civil war two years ago.
Congo's neighbours, Rwanda and Uganda, have been accused in the past of using the local militias as proxies, to further their own interests in the region.
For Ituri's civilians, it means the nightmare continues.
Up to 50,000 have been killed since 1999, and rape is still widely used as a weapon of war.
The UN estimates that within the provincial capital Bunia alone there are 50 new cases of sexual violence every week.