The UN says about 200,000 people have fled the area since August
Rebels fighting government troops in the Democratic Republic of Congo have captured a major army camp in the east of the country, UN peacekeepers say.
The rebels have also taken control of the headquarters of Virunga national park, home to some of the world's last remaining mountain gorillas.
Clashes between the supporters of renegade general Laurent Nkunda and the army are continuing.
Residents are fleeing the area as the army attempts to recapture the base.
About 200,000 people have fled their homes since fighting resumed in the area in late August.
This is the second time Gen Nkunda's supporters - who say they are protecting the area's Tutsi minority - have taken control of the Rumangabo camp.
They defeated about 1,500 troops there three weeks ago.
UN peacekeepers deployed in the region say fighting between government troops and the rebels is continuing as the army attempts to recapture the camp.
An unknown number of rebels, government soldiers and civilians have been killed.
The fighters have also taken control of the headquarters of Virunga National Park, home to some of the world's last remaining mountain gorillas and a Unesco World Heritage Site.
"The seizure of our Park Headquarters at Rumangabo by rebels is unprecedented, even in all the years of conflict in the region," said Park Director Emmanuel de Merode, adding that the conflict on the ground is "chaotic and dangerous".
Over 50 of the park's rangers have been forced to flee into the forests.
"When the rebels started approaching the park station we thought we were all going to be killed," Park Ranger Bareke Sekibibi, 29, was quoted as saying in a statement.
"We are not military combatants, we are Park Rangers protecting Virunga's wildlife," he added.
Ten mountain gorillas from Virunga were killed in 2007
Virunga, which borders Uganda and Rwanda, accommodates 200 of the last remaining 700 mountain gorillas in the world. The mountain gorillas are an endangered species.
The statement said the Gorilla Sector was attacked repeatedly in 2007 during which 10 mountain gorillas were killed.
Eastern DR Congo is facing a humanitarian crisis, with more than a million people displaced by repeated waves of fighting between rebel groups and the Congolese military.
The United Nations says many of those who fled are malnourished and some are dying of hunger.
The UN has some 17,000 peacekeepers in DR Congo and despite intervening to try to keep the two sides apart, they have failed to halt the violence.
A peace deal was signed in Goma at the end of January between the government and various rebel groups.
Although he signed the deal, Gen Nkunda he has always refused to disarm while Rwandan Hutu rebels still operate in the area.