The rebels said they were closing off camps south of Kisangani to restore order after the slaughter of six Zairian villagers sent local residents on a rampage, looting and stoning foreign journalists and aid workers. It was unclear who the killers were.
International agencies already had suspended aid shipments because of such attacks, but wanted rebel assurances they could safely return and prepare for a planned airlift of the refugees home to Rwanda.
Instead, the rebels told them yesterday to stay away. The refugees - dying at a rate of 60 per day from malaria, dysentery, pneumonia and cholera - have enough food to last about two days.
"We're concerned about what's happening in the camps, because we've got nobody there," said Paul Stromberg, spokesperson for the U.N. High Commissioner for Refugees. "We're concerned that in present circumstances, they may leave."
UNHCR planned to fly over the camps today to see whether refugees were fleeing, Stromberg said.
The United Nations condemned recent attacks by Zairian mobs, including yesterday's, and linked them to rebel stalling of what would be the biggest refugee airlift in Africa. The United Nations wants to fly the 100,000 refugees south of Kisangani to the Rwandan border, then repatriate them.
U.N. Secretary-General Kofi Annan and U.N. High Commissioner for Refugees Sadako Ogata met yesterday in Geneva. Ogata said the situation had worsened since Zairian mobs stoned the cars of foreign aid workers on Friday.
"Today, the military told us that we would not be allowed in the camps," Ogata said in a statement. "That is not good enough. We must have access and we must begin the airlift."
The airlift originally was to have begun Friday, but rebels have delayed it, saying an airlift would spread disease and clog rebel-held airports.
Instead, the alliance wants trucks to take the refugees on the 375-mile drive to the border. Parts of the road are in such bad shape that extensive repairs would be needed first.
Already tense relations between Zairians and Rwandan refugees worsened yesterday, when assailants with machine guns shot and killed six villagers in their mud huts in Kasese, 15 miles south of Kisangani.
It was not known who committed the attack, but villagers claimed to hear the killers speaking the Rwandan language, Kinyarwanda, and blamed Rwandan Hutu militiamen from the refugee camps. Many ethnic-Tutsi rebels also speak Kinyarwanda.
Asida Musalia said the attackers ordered him to go in his hut. "Then, I heard gunshots around the village, and when I came out I saw them run into the jungle."
Nearby, a woman wailed over the bullet-riddled body of her 17-year-old son. In the next house, an elderly women and a young girl lay dead on the mattress. The door had been forced open, and shells were scattered on the ground.
After the killings, mobs of Zairians looted a World Food Program warehouse near Kasese and a trainload of food near a rebel army checkpoint about 10 miles to the south. Nearby rebel fighters did not try to protect the food, intended for Rwandan refugees.
Brenda Barton, of the WFP in Nairobi, Kenya, said the mobs stole about 200 tons of food, which could take days to replace. "We're pretty much wiped out," she said.
The mob in Kasese also stoned foreign reporters and aid workers, and struck an Associated Press Television reporter in the neck with a stick. Nobody was seriously injured.
The Hutus at the camps in central Zaire are among more than 1 million Rwandans who fled their country in 1994, fearing retaliation from the new Tutsi-led government for the previous, Hutu-led government's slaughter of a half-million people.