GOMA, Congo (AP) — Thousands of people are without access to medical care and their lives at risk after they fled fighting between the army and a local militia in southeastern Congo in recent days, Doctors Without Borders said Friday.

The exodus from villages and into the bush follows an army operation that started two weeks ago in Katanga province against loyalists of Gedeon Kyungu Mutanga, a local warlord who escaped in a mass prison break in 2011 while serving a conviction of crimes against humanity.

Doctors Without Borders said thousands of people can no longer access its medical facilities, most children in its nutrition programs have left, and a measles vaccination campaign has been suspended — just as malaria cases spike with the onset of the rainy season.

The group said it wasn't clear how many people had fled, but a string of villages had emptied.

"The population is really afraid. The clashes have brought back a lot of terrible memories for these people. There have been rumors about troops' movement and people fled into the bush," said Anne Marie Loof, a worker with the international aid group who recently came back from a mission in the region.

Between 2003 and 2006, Gedeon's militia burned and pillaged countless villages, was behind hundreds of killings, and provoked the displacement of more than 150,000 people in the area — since nicknamed the "Triangle of Death" by some locals.

He was arrested in 2006 and convicted of crimes against humanity in a landmark trial for Congolese justice three years later.