Government troops in the eastern Democratic Republic of Congo have exchanged fire with dissident fighters after several soldiers were killed in an ambush. As violence increases, U.N. officials are warning that hundreds of thousands of people could swell the number of displaced people in the unstable region. Selah Hennessy reports from VOA's West and Central Africa Bureau in Dakar.

Residents in the area say exchanges of heavy weapons and machine gunfire took place overnight near the town of Behambwe.
 
The fighting closely followed Monday's deadly ambush.
 
U.N. military spokesman Frederic Medard says a Congolese brigade commander's car was attacked by unknown fighters.

"In North Kivu yesterday there has been an ambush led against an FRDC [Congolese army] brigade commander who fortunately was not in his car, but they reportedly lost ten soldiers in the ambush," he said.
 
He says the attack was against a mixed brigade, composed of both regular army troops and former rebels. The mixed brigades were formed earlier this year following intense fighting between the army and ethnic Tutsi dissident fighters, who are led by renegade army general Laurent Nkunda.
 
But tensions remain between the two forces. Residents say security has actually worsened in the region since the brigades began deploying in January.
 
Congolese army commanders have blamed Monday's attack on troops loyal to Nkunda, some of whom have been deserting ranks in recent days.
 
U.N. spokesman Medard says loyalties within the mixed brigades are conflicting.

"You have battalions probably loyal to Laurent Nkunda and also loyal battalions to the Congolese government in the same brigade, so it is difficult to know what they are currently doing," he noted.

The United Nations has warned that the increase in violence in the region is forcing many Congolese to flee their homes.
 
Christophe Illemassene is the head of public information and advocacy at the United Nations Organization for Coordination of Humanitarian Affairs.
 
"Since January this year we have had 168,000 newly displaced people," he said.  "The overall number of displaced people that we have for North Kivu is 640,000."
 
He says humanitarian groups fear these numbers could swell.
 
"One of the scenarios that we are looking into, should fighting intensify in that province in North Kivu, we could expect almost up to 330,000 more newly displaced people," he added.
 
Nkunda says his fighters are making sure ethnic Tutsis are being protected against ethnic Hutu fighters, some of whom took part in Rwanda's genocide, and fled across the border.  Congo's army recently stopped a military campaign against armed groups in the east, angering both General Nkunda and Rwanda's government.
 
Soldiers, Hutu rebels, and dissident Tutsis all have set up roadblocks for extortion in the mineral-rich region, and compete over territory.
 
Regional military chiefs met in Kigali this week to reassess the tenuous border situation.