Heads of states involved in the conflict were due to finalise a ceasefire at a summit in the Zambian capital, Lusaka, on Monday.

The Zambian Foreign Affairs Ministry said the meeting was being postponed until the new year but gave no reason for the decision.

Unconfirmed reports say it was put off because intense diplomatic efforts had failed to secure sufficient progress on a peace plan proposed by the Organisation of African Unity.

Earlier attempts to find a peace agreement have failed as the Congo President, Laurent Kabila, has refused to talks with the rebels.

The rebels are supported by Uganda and Rwanda. President Kabila says he is not facing a rebellion but an invasion.

Congo is being backed by an alliance of neighbouring nations including Angola, Zimbabwe, Namibia and Chad.

Fighting began in August when rebel forces marched on the Congolese capital, Kinshasa.

Large sections of eastern Congo are in the hands of the rebels but Kinshasa has remained under government control.

Some regional analysts had thought that domestic issues for President Kabila's allies could divert their attention away from the Congo conflict.