UN Human Rights Commissioner Emma Bonino criticises Rwanda's role in the region

The Tutsi-led rebels are reported to have captured the strategic petroleum-producing town of Muanda on the Atlantic coast, as well as another town, Uvira, on the eastern border.

But a senior government official said reinforcements loyal to Mr Kabila had been sent in and a major battle was raging for control of the area.

Laurent Kabila led Tutsi rebel soldiers to overthrow Mobutu last year

Muanda is close to the hydro-electric dam on the Congo river which feeds much of the country with its power.

It is also crucial because a petrol pipeline from the region and the nearby port of Makadi feed the capital with its fuel and imports.

Meanwhile, more than 100 ethnic Tutsi soldiers have fled into neighbouring Zambia after clashes with forces loyal to Mr Kabila.

Some allege that fighting broke out after government troops carried out atrocities. One said President Kabila's troops had poked their comrades' eyes out of their sockets.

Rwanda "not to blame"

Congolese Justice Minister Mwenze Kongolo: "We have to defend our land"

Mr Kabila's Justice Minister, Mwenze Kongolo, has blamed Rwanda for the fighting.

He denied the unrest was a rebellion by disaffected soldiers.

But Rwanda's President, Pasteur Bizimungu, who is currently visiting Zambia, denied his country's involvement in the Congo rebellion.

Senior Rwandan official Emmanuel Gasana: "We have had no contact with the rebels"

President Bizimungu did not rule out future involvement and added: "If we have serious reasons to be involved maybe we should."

US warning

His comments came after the United States warned neighbours of the Democratic Republic of Congo, formerly Zaire, not to get involved in the rebellion against President Kabila.

A US State Department spokesman said Washington was concerned by reports that the Rwandan army, which is dominated by Tutsis, had been helping the rebel forces.

News reports suggest the eastern town of Bukavu, close to the Rwandan border, is in rebel hands but the country's third largest city, Kisangani, is still under government control.

Mediation efforts

Zimbabwe is organising a regional summit this weekend in a bid to deal with the unrest in the Democratic Republic of Congo and the Great Lakes region in general.

The conference is due to start on Friday afternoon in the Zimbabwean town of Victoria Falls.

The presidents of Uganda, Rwanda, Tanzania, Namibia, Zambia and the Democratic Republic of Congo are reported to have confirmed their attendance.