|Fighters of the CNDP have been accused of killing off a frequently-broken ceasefire [AFP]
The National Congress for the Defence of the Peoples (CNDP) has been fighting its way towards the town of Rutshuru, about 100km from North Kivu's provincial capital Goma, as part of its latest offensive, which began on October 26.
The fighters under General Laurent Nkunda launched their offensive on Sunday, advancing to within 20km of Goma, and forcing UN peacekeepers to use helicopter gunships in response.
The Democratic Republic of Congo (DRC) has tried to pacifying the east but has so far failed to fully end the conflict that has raged during the past 10 years. Fighting breaks out sporadically, threatening to push Africa's largest country into full-scale war.
In 2003 the warring factions signed a deal creating an interim constitution and a transitional government, and in December 2005 a referendum paved the way for national elections which were finally held in July and Ocotber 2006.
Joseph Kabila, son of Laurent Kabila, a former president who was assassinated in 2001 as the country was on the verge of callapse, was sworn in as president of the DRC in December 2006.
Instability in the country, which is rich in mineral deposits, has ramifications for neighbouring countries in the Great Lakes region.
Origins of conflict
The roots of Laurent Nkunda's rebellion lie in the ethnic and political tensions that have persisted in the east of the country since the Rwanda genocide of 1994.
During the three months of bloodshed - in which 800,000 Tutsis and moderate Hutus were killed by the Hutu-led government and ethnic militias - both Tutsi and Hutu fighters fled over the border.
Hutu militias entered Congo as the Rwandan Patriotic Front/Army, which took power in 1994, advanced on Rwanda's capital, Kigali.
|General Nkunda says he is fighting to protect the Tustis against the FDLR [File: AFP]
Their presence encouraged Tutsis to invade from Rwanda and this in turn helped spark Congo's wider 1998-2003 war, drawing in six African countries, some from the Great Lakes Region and Southern Africa.
An estimated 5.4 million people have died during the conflict, partly as a result of the fighting and through hunger and disease.
Nkunda led 4,000 soldiers to rise up and capture the South Kivu capital of Bukavu in 2004. An international arrest warrant was issued for him for war crimes committed while occupying the city, but Congolese officials say this has expired.
After elections in 2006 aimed at drawing a line under the war, Joseph Kabila, the president, promised to bring peace to his country's eastern districts.Accusation
Nkunda has said he is fighting to protect his Tutsi people in the east against attacks by the Democratic Forces for the Liberation of Rwanda (FDLR), a Rwandan Hutu group which controls parts of North Kivu.
He says Kabila's government backs the FDLR, a charge the government denies.
The FDLR includes Rwandan ex-soldiers and members of Hutu Interahamwe militias which had participated in the Rwandan genocide.
The present fighting is deepening an already critical humanitarian situation in North Kivu, where 850,000 people are already displaced by fighting which began in August, UN figures indicate.
Since then, 250,000 people have escaped, many of them forced to move on several times as the focus of the fighting shifts.
In August, Nkunda's fighters pulled out of a tenuous peace process, effectively ending a fragile ceasefire dating back to a January 2008 peace deal.
Nkunda's men and government troops each accuse the other of provoking clashes.
The UN peacekeepers, Monuc, blamed Nkunda's troops for instigating most of the recent fighting and called on militias in the east to abide by the January peace agreement. Nkunda accuses Monuc of bias.
Source: Al Jazeera and agencies