KIWANJA, Congo - Congo's fragile ceasefire appears to be unravelling.
The UN says fighting between rebel leader Laurent Nkunda's insurgent forces and the Congolese army has spread to another town in the volatile country's east.
Madnoje Mounoubai, a spokesman for UN peacekeepers, says the latest clashes took place Thursday in the town of Nyanzale in North Kivu province.
Speaking from behind rebel lines west of Kiwanja, Nkunda told The Associated Press that army forces backed by pro-government militias attacked rebel positions before dawn in Nyanzale.
But he says the army later abandoned its positions "and a large number of displaced also fled the combat" and sought shelter near a UN base.
Mounoubai said the army had also taken part in fighting Saturday in two other towns in the region: Mweso and Kashuga.
Meanwhile, Nkunda, the rebel leader, reiterated Thursday a threat to march on Congo's faraway national capital.
"This is a treasonous government that is betraying the people of Congo and that is why we will continue to fight until we reach Kinshasa," he said.
The violence dealt another blow to a unilateral ceasefire Nkunda declared Oct. 29 as his fighters reached the outskirts of the main provincial city of Goma, suddenly halting a lightning advance that forced Congo's army into a humiliating retreat.
Nkunda had already accused the army of firing mortars toward rebel positions from behind militia lines during battles Tuesday and Wednesday around Kiwanja, about 70 kilometres north of Goma, which forced thousands of civilians to flee.
Low-level fighting has ground on in Congo for years, but clashes intensified in August and have since driven around 250,000 people from their homes.
Nkunda is demanding direct negotiations with President Joseph Kabila's government, which says it will only meet with all militia groups in the region, not just with Nkunda.
Dozens of militia groups operate in the remote terraced valleys and hills of eastern Congo, a lawless region that the government and a 17,000-member UN peacekeeping mission have struggled to bring under control for years.
Among the armed groups are pro-government militias known as the Mai Mai, and ethnic Hutu insurgents from Rwanda who fled to Congo after helping carry out Rwanda's bloody 1994 genocide.
Kabila, Rwandan President Paul Kagame and UN Secretary General Ban Ki-moon are to attend a UN-backed African Union summit expected Friday in Nairobi, Kenya. Kagame is believed to wield strong influence over Nkunda's Tutsi-led rebels.
Ban said Wednesday he would "sit down together with President Kabila and President Kagame and encourage them to find a path to peace."
Asked whether he would encourage Kabila to open a direct dialogue with Nkunda, Ban said: "I will certainly encourage him to engage in dialogue with whoever, including Nkunda. I will discuss this matter with President Kabila."
The conflict in eastern Congo is fuelled by festering ethnic hatred left over from the 1994 slaughter of a half-million Tutsis in Rwanda, and Congo's civil wars from 1996-2002, which drew neighbouring countries in a rush to plunder Congo's mineral wealth.
Nkunda, who defected from Congo's army in 2004, claims the Congolese government has not protected ethnic Tutsis from the Rwandan Hutu militia that escaped to Congo after helping slaughter a half-million Rwandan Tutsis. Critics say Nkunda has exaggerated the threat against Tutsis and is a puppet of neighbouring Rwanda.
