Thousands of people are fleeing a fresh outbreak of fighting in Kivu in the eastern Democratic Republic of Congo.
Aid agencies are warning of a worsening humanitarian crisis
Clashes between local militias and the dissident army general, Laurent Nkunda, in Bunagana sent refugees flooding into the nearby town of Rutshuru.
There are also reports of fighting between government forces and rebels in Bukima town, in the same district.
The clashes follow government threats to Gen Nkunda's troops to reintegrate into the army or face an offensive.
Gen Nkunda ignored a Monday deadline to begin disarming his troops.
The deadline has since been extended to an unspecified date, and government troops have advanced on Gen Nkunda's stronghold of Kichanga in the past week.
More than 370,000 people have been displaced by the fighting in eastern DR Congo since the start of the year, and on Saturday thousands more were on the move, trying to escape fresh outbreaks of violence.
Early in the morning refugees began arriving in Rutshuru in North Kivu province, reports said.
They had fled from the border town of Bunagana, where clashes were occurring between Congolese Mai Mai militias and Gen Nkunda's forces.
"What I saw was horrendous. It was raining. They didn't know where to go. Three women gave birth while they were fleeing," Sylvie Van Den Wildenberg, a spokeswoman in North Kivu province for the UN peacekeeping mission Monuc, told Reuters news agency.
"The humanitarian consequences of whatever is happening there are very serious."
Some refugees are being held in a stadium as they wait for room in a nearby refugee camp.
Other refugees from Bunagana are said to have fled over the border into Uganda.
There were separate reports of fighting in Bukima, in the same district as Bunagana.
KEY FORCES IN THE KIVUS
FLNK - new group made up mainly of Congolese Mai Mai with some Rwandan Hutus formerly in the FDLR
FDLR - Hutu militia made up of former Rwandan soldiers and others who fled into Congo after the 1994 genocide
Gen Laurent Nkunda, with an estimated 5,000 soldiers
Monuc - UN Mission in the DR Congo
The deputy commander of the government forces in North Kivu, Col Delphin Kahimbi, told the BBC's Arnaud Zajtman there had been clashes between Gen Nkunda and regular troops.
The renewed fighting comes after Gen Nkunda ignored Monday's deadline to disarm his men. On Wednesday, President Joseph Kabila told the army to prepare for the forced disarmament of Gen Nkunda's fighters.
Our correspondent says government troops and local militias are trying to weaken and isolate Gen Nkunda's men, and to cut him off from supplies of arms and munitions coming from across the border.
Medical staff have charged authorities with blocking medical supplies to Gen Nkunda's stronghold of Kichanga. They complain that such measures impact hard on civilians.
Gen Nkunda - whose forces are primarily ethnic Tutsi - has accused government forces, Mai Mai militia and Rwandan Hutu rebels operating in the area of colluding against him.
The government denies this, and says it has run out of patience with Gen Nkunda.