More than 500 people were alleged to have died in the attack.

Information Minister Didier Mumengi said on state radio that the government was observing the ceasefire agreement brokered by Zambia and accused the rebel Congolese Liberation Movement (MLC) of fabricating the allegations in order to keep the war going.

Mr Mumengi said the rebels - who are backed by Uganda, should turn their attentions to Sudan - whose planes, they alleged, were involved in the attack.

Jean-Pierre Bemba, head of the MLC, said aircraft had dropped 18 bombs on Makanza and Bogbonga, about 620 miles north-east of the capital, Kinshasa.

He said 384 civilians and 134 rebel soldiers were killed.

If confirmed, the raid would be one of the deadliest single attacks during the year-long civil war in the Congo.

The government and the MLC signed a ceasefire agreement on Sunday. The status of this is now unclear.

Zambian diplomacy

In efforts to secure a complete ceasefire, Zambian President Frederick Chiluba has sent his special envoy to eastern Congo to resolve a dispute within the main rebel movement fighting the Congolese Government.

Divisions within the Congolese Rally for Democracy have prevented them signing the agreement reached last month in Lusaka between all six countries involved in the war.

The Zambian envoy, Eric Silwamba, will meet the two rival rebel leaders, Emile Ilunga and Wamba dia Wamba at their headquarters in Goma and Kisangani.

He said his mission was to try and harmonise rebel positions.