Nairobi/Goma - The Congolese army and Tutsi rebels have been involved in some of the worst clashes for a week despite rebel leader Laurent Nkunda telling a United Nations envoy that he supports peace in eastern Democratic Republic of Congo, the UN said Monday.

"Yesterday we had a lot of clashes in Riwindi (125 kilometres north of Goma, the capital of North Kivu province) and its outskirts," Lieutenant Colonel Jean-Paul Dietrich, military spokesman for the UN peacekeeping mission in DR Congo, told Deutsche Presse-Agentur dpa.

Dietrich said there was heavy firing between Nkunda's National Congress for the Defence of the People (CNDP) and the Congolese army from early afternoon until late evening.

The CNDP seized control of the Riwindi area during the fighting, which saw a UN peacekeeper at a nearby base lightly injured in the crossfire.

No further exchanges of fire were reported Monday morning.

The clashes took place as Nkunda told UN peace envoy Olusegun Obasanjo, the former president of Nigeria, that he would stick to a ceasefire and support a UN-backed peace process.

Nkunda called a ceasefire over two weeks ago as his troops were on the verge of taking Goma.

There have been repeated clashes despite the ceasefire, and Dietrich said that the CNDP was intent on gaining ground.

"They are now trying to move northwards to take Kanyabayonga (175 kilometres north of Goma)," he said. "In the last ten days or more they have taken more and more terrain under their control."

Government soldiers looted from civilians and also raped women last week as they retreated from Kanyabayonga area.

Aid agencies say that renewed fighting between Nkunda's National Congress for the Defence of the People (CNDP) and government forces has displaced at least 250,000 people since late August.

Poor security has impeded access to the displaced, but a World Food Programme convoy on Friday succeeded in crossing the front lines to deliver food to tens of thousands in the towns of Rutshuru and Kiwanja.

Nkunda, who has repeatedly said he will respect the ceasefire while fighting has continued, also told Obasanjo he wanted direct talks with the DR Congo government.

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.

The government dismisses Nkunda as a war criminal and refuses to meet him.

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

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.

There have been persistent reports of Angolan soldiers on the ground in the DR Congo during the last few weeks of fighting. Angola denies it has provided troops, but southern African leaders have said they will send a peacekeeping force if necessary.

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)