THE UN Security Council yesterday authorised an international force to prevent a humanitarian catastrophe in eastern Zaire despite the exodus of hundreds of thousands of refugees back to Rwanda.

In a resolution, the 15 member body approved the Canadian led force for Zaire until March 31 to allow relief workers to feed and clothe the refugees, many of whom have fled westwards into the Zairean hinterlands.

The resolution allows the troops to use "all necessary means" to defend themselves. But Canadian Lt Gen Maurice Baril, designated commander of the force, said the foreign soldiers would not attempt to disarm Hutu militia among the refugees.

As the council put the finishing touches to the document, large numbers of refugees abandoned: teeming camps in Mugunga near Goma, Zaire, and began the trek back into Rwanda, apparently free of militia troops who had blocked their return.

Rwandan officials immediately said the exodus meant the force was no longer needed and the world should send aid to his country instead. But chief UN spokeswoman Sylvana Foa said most of the remaining refugees still lacked basic necessities and needed logistical support only the military could provide.

Ms Foa expressed delight that huge numbers of Rwandan refugees were streaming home but insisted a multinational force was still badly needed.

She said the Geneva based UN High Commissioner for Refugees had called the exodus the "largest and fastest homeward movement of refugees in history".

The multinational force, expected eventually to number some 10,000 troops, is to use "all necessary means" to get food, water and medical supplies to more than a million Rwandan Hutu refugees. The 700,000 Hutu refugees who abandoned camps in east Zaire yesterday to trudge back to Rwanda left behind mutilated corpses of a handful of men, women and children and a mystery as to how they died.

Meanwhile, a former Vietnam war paratrooper is likely to be named as head of the American contingent of forces, a US military official said. The officer is Maj Gen Ed Smith, currently in charge of the US army's Southern European Task Force in Italy. Gen Smith was in Central Africa yesterday leading a vanguard of some 40 American soldiers engaged in preparatory work.

Hutu militia and Rwandan exgovernment soldiers had made Mugunga camp a base in exile after fleeing to Zaire in 1994. Zairean rebels bombarded the camp on Thursday, triggering the exodus.

The UN's World Food Programme, waiting on the Rwandan, side of the border with food, said up to 10,000 had already crossed with a further 275,000 backed up along the road.

The Rwandan President, Mr Pasteur Bizimungu, a Hutu, went to the Gisenyi border post to welcome his countrymen.

"We have come here to welcome the people to show them the whole population was waiting for them to reassure them there won't be any harassment. They are welcome in Rwanda," he said.

But underlining the volatile nature of the region, Zaire said it would wage war on Burundi and Rwanda, which it accuses of violating its territory in fighting in its east.

"We are determined to wage a total war... We have the means," the Zairean Deputy Foreign Minister Mr Lokondo Yoka, told a news conference in Brussels.

Zaire's ragged army is outnumbered by Rwanda's 54,000 strong force which is dominated by Tutsis who swept the then Hutu led government from power in 1994 following the genocide.

In Geneva, the World Health Organisation said cases of cholera had been confirmed in eastern Zaire and it feared further outbreaks in the strife torn area.

Laboratory tests on samples taken from 14 Zairean patients, who arrived in Goma's central hospital from the town of Sake, have confirmed cholera, according to the UN agency. A medical charity said earlier this week that an Argentine doctor was battling alone to treat cholera sufferers among a mass of Rwandan Hutu refugees near the town of Mwenga.