In this story:

• 'Heading for catastrophe'
• Regional nations have vested interest
• Open recruitment in Kinshasa
• Weapons come from abroad
• International community must act
• Related stories and sites

KINSHASA, Congo (CNN) -- While heavy fighting continued unabated between government troops and rebels trying to oust President Laurent Kabila on Tuesday, a U.N. report warned of an impending catastrophe and the threat of mass killings.

Mahmoud Kassem of Egypt, the main author of the report, said that fighters from the former Rwandan Hutu army and its militia supporters had become significant players in the Democratic Congo, battling alongside Kabila's forces.

Many soldiers from the former Rwandan army, known as ex-FAR, and their Interahamwe militia allies, were implicated in the 1994 genocide in Rwanda, where more than 500,000 Tutsis and moderate Hutus were massacred.

'Heading for catastrophe'

"The situation in the region is rapidly heading for a catastrophe. The danger of the repetition of the tragedy comparable to the Rwandan genocide of 1994, but on a sub-regional stage, cannot be ruled out," Kassem said in the report, which was published on Monday.

He said some 20 rebel groups, in addition to those from Rwanda, are now operating in the region and forge links with other armed groups in Angola, Burundi, Uganda and elsewhere.

"But this time the rebel groups are not only aligned among themselves but they are aligned with governments who are using them for their own purposes," he said. "They have a kind of form of legitimacy they did not have before."

Regional nations have vested interest

Remains of the 1994 Rwandan genocide

When the minority Tutsis took over Rwanda after the genocide, Hutu civilians and fighters fled to neighboring Congo, then Zaire. Once Kabila, with the help of the Rwandan Tutsi army came to power a year ago, the Hutus fled again.

But alliances changed rapidly in August when Congolese rebels, backed by Rwanda and Uganda, took up arms against Kabila. In turn, Angola, Namibia, Chad and Zimbabwe have deployed troops, tanks and planes to help Kabila.

The report by Kassem's Commission of Inquiry, which was commissioned by the Security Council in 1995 on how the Hutu fighters received weapons, said the new turmoil in the Congo had given Rwandan rebels am unexpected advantage.

"The ex-FAR and Interahamwe, once a defeated and dispersed remnant, have now become a significant component of the international alliance against the Congolese rebels and their presumed sponsors, Rwanda and Uganda," the report said.

Open recruitment in Kinshasa

In tracing the Rwandan rebels, the report said that hundreds of Hutus had been "openly recruited in Kinshasa" to fight for Kabila and some 10,000 others flooded into the country from refugee camps in the Central African Republic, the Congo Republic, Tanzania and elsewhere.

There was evidence, it said, they also were training in the Sudan and had received arms supplies from Khartoum. The Rwandans have forged close ties with Burundian Hutu rebels and have taken part in attacks against that country's Tutsi army.

But the turmoil also created strange bedfellows, with some Rwandan rebels aligned with Angola's rebel UNITA movement, which opposed the Kabila government.

Weapons come from abroad

Kassem said in 1996 it was easier for his commission to trace weapons to governments in Eastern Europe. "But now so many governments are taking part and they supply them with money, arms and training," he said.

Nevertheless, the report said the French government had not yet examined South African arms dealer Willem Ehlers connection with the Banque National de Paris. Ehlers had long been cited in supplying arms to the Hutus.

Similarly, Bulgaria had not answered reports that two of its chartered air companies sent arms to the Rwandan rebels.

But Britain conceded that its Mil-Tec Corporation, registered in the Isle of Man, may have circumvented a 1994 U.N. arms embargo. It said the firm would not be prosecuted because British legislation at the time on the embargo did not cover neighboring countries, according to the report.

The commission traveled to Kenya, among many other countries, where the report said the commission members suspected a sophisticated fund-raising and Rwandan intelligence network in Nairobi.

Some of the money also came from drug trafficking. The report said the Rwandans appeared to be involved in smuggling mandrax, a hallucinogenic drug, to South Africa from India and other Asian nations via Kenya.

International community must act

The commission recommended that African nations adopt and enforce legislation against arms smuggling and initiate moratoriums on imports and trade in weapons.

It also said the European Union should make the price of joining the EU a commitment to monitor arms transfers to conflict zones.

EU special envoy Aldo Ajello said Monday that Brussels would like to play a more active role in helping end the conflict. But he also said that the EU had no intention of interfering in "existing African initiatives," such as the peace efforts currently under way by the Southern African Development Community.

The SADC has been talking to both Kabila and the rebels and is pushing a peace plan that would include a cease-fire as the basis for further negotiations.

Despite the international mediation efforts, fighting has been going on daily. Latest reports about the fighting carried by Congolese state radio spoke of air raids against rebel positions with Zimbabwean military aircraft. Hundreds of rebels were killed, according to the radio. But there has been no independent confirmation of those reports.

The Associated Press and Reuters contributed to this report.