In a report to the Security Council, the panel said the theft of Congo's natural riches was fueling the two-and-a-half-year civil war, which had turned into a lucrative business venture for all the combatants to the point where enemies sometimes joined forces to make money.
"All the belligerents in one way or another are benefiting from the conflict," panel chairman Safiatou Ba-N'Daw, a former Ivory Coast energy minister, told a news conference launching the report. "The only losers are the Congolese people."
The panel called for trade sanctions against Rwanda, Uganda and Burundi; demanded an immediate arms embargo against rebel groups operating in Congo and the freezing of their assets.
It did not call for any action against the government's supporters Zimbabwe, Angola and Namibia.
Francois Mwamba, the Congolese Liberation Front's finance secretary, said the authors of the report failed to meet with him or any other northern rebel leader to discuss exports.
The Rwandan-backed Congolese Rally for Democracy (RCD) which controls eastern Congo withheld comment on the U.N. report until it had had a chance to review it. But Patrick Mazimhaka, Rwanda's envoy to Congo, said the report was biased.
"By targeting the rebels and their backers, the U.N. is fighting the Kinshasa (government) war," Mazimhaka said. "It is a report the U.N. should be ashamed of, as it is totally biased against one side in the conflict, relying heavily on hearsay and quoting unnamed and biased sources who have grievances against Rwanda."
John Nagenda, a senior media adviser to Ugandan President Yoweri Museveni, also questioned the qualifications of the report's authors.
"The report comes out like gossip. It does not read like a proper report. It reads like a slapdash report," Nagenda said.
Mwamba said his group issues licenses, collects taxes and ensures exporters operate under international norms. Concessions are issued by local leaders, and anyone can do business in northern Congo, not just Ugandans.
"You can find people here from Lebanon, Central African Republic and Belgium doing business," Mwamba said Sunday.
Both rebel groups have become increasingly frustrated with what they see as United Nations bias in the peace process.
The RCD on Sunday denied U.N. peacekeepers permission to deploy in Kisangani because U.N. officials refused to condemn cease-fire violations by government forces.
The rebels accuse government forces of going on a rampage in the Eastern Kasai province, killing and raping civilians and burning houses in an area rebels vacated under a disengagement plan signed by parties fighting over Africa's third largest country.
MONUC said at the weekend that it had sent a team on Saturday to investigate the alleged violations, said to have happened on April 6, but a report might not be ready for a week. The RCD relented Tuesday, saying it was "satisfied" and would allow the deployment.
Some 2,500 U.N. troops are eventually due to guard 500 unarmed observers, a tiny group to monitor a country the size of Western Europe where roads have crumbled after decades of conflict and corrupt mismanagement.
Rebels fighting to overthrow the Kinshasa government began the war in 1998 with the help of Uganda, Rwanda and Burundi. Zimbabwe, Angola and Namibia rushed to help the government.
A 1999 cease-fire was never fully implemented, but the search for peace gained momentum following Laurent Kabila's assassination in January and the succession of his son, Joseph, to the presidency.
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