A rebel general in eastern Democratic Republic of Congo has called on the government to return to a peace process, after intense fighting.
Gen Nkunda says he is protecting ethnic Tutsis
The United Nations says it is backing Congolese government troops in their intensifying fight against rebels led by General Laurent Nkunda.
The Congolese army has deployed a helicopter gunship against the rebels.
Clashes are continuing in two parts of North Kivu province, including in a park inhabited by mountain gorillas.
Some 170,000 people have fled the area this year, says the UN refugee agency.
Mr Nkunda told the BBC's Network Africa programme that he was looking for security and a return to the peace process.
"It's the government side who have broken the peace process," he said. "We are asking the government to get back on the peace process, because it is the real way to resolve the Congolese problem."
The UN's military spokesman in the Democratic Republic of Congo, Major Gabriel de Brosses, told the BBC it was airlifting government troops and ammunition to North Kivu.
Mr Nkunda denied that his forces have been behind the violence that has caused thousands of civilians to flee their villages.
"Those are lies, are not real, they are allegations," he told the BBC. "We were attacked."
On Tuesday, government forces used an Mi-24 gunship in a strike against rebels some 80km (50 miles) west of the regional capital, Goma, Colonel Delphin Kahimbi told the BBC.
BBC World Affairs Correspondent Mark Doyle says the use of helicopter gunships marks a significant escalation in the conflict.
A Congolese general claimed about 80 rebels had died in the attack, though this has not been independently confirmed.
The army says that 180 rebel fighters have now been killed in recent days.
Conservationists are increasingly concerned for the remaining 700 mountain gorillas in the Virunga National Park.
Nine gorillas have been killed this year, allegedly by Gen Nkunda's men, sparking outrage among conservationists.
Gen Nkunda's forces are believed to have moved into the park in pursuit of Rwandan Hutu rebels, who have bases there.
Gen Nkunda, a Tutsi, has accused the government of forming an alliance against him with the Hutu FDLR, accused of involvement in the 1994 Rwandan genocide of Tutsis.
After Tutsis took control in Rwanda, they crossed the border into eastern DR Congo.
The United Nations says up to 10,000 people have fled the latest fighting into Uganda.
Nine gorillas have already been killed this year
The UN refugee agency says it is organising shelter for those who fled the violence Monday night and wish to stay on the Ugandan side of the frontier.
Following a visit by Rwandan Foreign Minister Charles Murigande to Kinshasa, DR Congo has promised to increase its operations against the FDLR.
Rwanda has twice invaded its large neighbour, saying it is trying to stop the FDLR from attacking its territory.
BBC Kinshasa correspondent Arnaud Zajtman says that the two countries are still divided by the same issues which have divided them for years - DR Congo wants Rwanda to rein in Tutsi fighters, such as Gen Nkunda, while Rwanda wants DR Congo to stop the activities of the Hutu rebels, known as the FDLR.