Nairobi/Goma - Congolese President Joseph Kabila has sacked his military chief of staff in the wake of rebel gains in the east of the Democratic Republic of Congo.

State television late Monday night said that General Didier Etumba Longomba, the navy chief, would take over from General Dieudonne Kayembe.

Rebel Tutsi general Laurent Nkunda's National Congress for the Defence of the People (CNDP) has routed the Congolese army in recent weeks and seized control of territory in the eastern North Kivu province.

Army discipline has broken down in many cases, with Congolese troops looting and raping as they retreated in disarray.

Aid agencies say that renewed fighting between the CNDP and government forces has displaced at least 250,000 people since late August, creating a humanitarian emergency.

Nkunda called a ceasefire almost three weeks ago as his troops were on the verge of taking Goma, but fighting has continued.

Sunday saw some of the worst clashes in a week. The fighting took place as Nkunda told United Nations peace envoy Olusegun Obasanjo, the former president of Nigeria, that he would stick to a ceasefire and support a UN-backed peace process.

The rebel general has warned that unless the government talks to him, his forces - believed to number between 4,000 and 6,000 - will march on the capital Kinshasa.

Nkunda was left out of talks in Nairobi on November 7, which were attended by UN Secretary General Ban Ki-moon, Kabila and Rwandan President Paul Kagame.

The UN peacekeeping mission in the DR Congo is overstretched and the head of the mission has called for more troops.

France has presented a draft resolution to the UN Security Council calling for 3,000 more troops. The motion is expected to go the vote next week.

There are fears that the fighting could reignite the 1998-2003 war, which sucked in many other nations, including Angola, Rwanda and Zimbabwe.

More than 5 million people are estimated to have died as a result of the five-year conflict in the resource-rich nation, most of them from hunger and disease.

The DR Congo accuses Rwanda of backing Nkunda, who says he is fighting to protect Tutsis from Hutu militia.

The armed Hutu groups were implicated in the 1994 massacres in Rwanda, when 800,000 Tutsis and moderate Hutus were killed. The Hutus fled to DR Congo after Tutsis forces led by Kagame seized power.

However, many observers say that the ethnic dimension is merely a pretext for various militia to seize control of land rich in gold, tin and coltan, which is widely used in electronic devices. (dpa)