The refugees were the lucky ones. Days later, piles of corpses bobbed like rag dolls in the Rusumo River. Rebel soldiers from the Tutsi-led Rwandan Patriotic Front, which seized the Rusumo Bridge, stared grimly into the muddy torrent as the bodies-mostly of women and children, some beheaded-cascaded by. The victims were almost certainly Tutsis, murdered by the rampaging government army and civilian militias from the minority Hutu tribe, who are seeking revenge for the death of Rwanda’s Hutu president in a suspicious plane crash on April 6. But the mass exodus from Rwanda is made up almost exclusively of Hutus, who fear reprisals from the advancing Tutsi rebel army. Just across the river in Tanzania, a barefoot army of about 200 Hutu peasants beaded for the makeshift refugee camp known as Benako. “We’ve walked for two weeks to escape the rebels,” said Paolo Yamulemie, 50, balancing a sack of his belongings on a rusty bicycle. “Now all we want to do is rest.”

At Benako camp, tens of thousands of ragged people mill along the muddy roads through the camp, or huddle under trees and plastic sheets that offer meager protection from torrential rains. Nobody is starving, because thousands of tons of food were stockpiled by relief agencies after a mass exodus from Burundi last fall; and many refugees arrived in the camp herding their goats and cattle ahead of them. But sanitation, shelter and clean water are in short supply, and aid workers are struggling to control outbreaks of diarrhea, malaria and respiratory infections. They also fear the eruption of fighting between Hutus and about 15,000 Tutsis who fled alongside them. Tanzanian soldiers confiscated thousands of machetes at the border, and relief workers suspect that some refugees are Hutu murderers who left Rwanda to avoid retribution for their crimes.

Rovina Ramazina, 35, says she was fetching water from a stream when rebel troops marched into her village, Kagasa. “They gathered the people in groups and began hacking them with pangas and machetes,” she says. She escaped with about 100 others. Jean-Bosco Gasana, 41, a Hutu schoolteacher, claims the troops shot down his mother, his sister and her three children in front of him. “The Hutus started the massacres, and the rebels then retaliated to avenge their Tutsi brothers,” he says. But most admit they didn’t witness killings by the rebels. “The RPF has a pretty clean slate,” says one top U.N. official in Kigali. “They’re going after militiamen but leaving civilians alone.” Most of the killing is being perpetrated by government troops and Hutu militias. In the provincial capital of Butare, militiamen invaded an orphanage last week and slaughtered dozens of children and Red Cross volunteers trying to protect them. In the southern border town of Cyangugu, 300 Tutsis were gunned down by soldiers after trying to flee to Zaire. The butchery in Kigali has died down only because, says one relief official, “there’s nobody left to kill.”

Trying to end the war, three U.S. State Department officials arrived to press for a cease-fire-signed last week by both sides-and drum up support for military intervention. Some diplomats have proposed that a force be assembled by the organization of African Unity and financed by Western donors. But U.N. officials in Kigali doubt that any African government will commit troops to the Rwandan chaos. The best hope for peace, they say, remains a rebel victory, which could be imminent: the guerrillas encircled Kigali and now control most of the country. But the tiny Tutsi minority won’t be able to govern the country alone. Without a power-sharing arrangement with the heavily armed Hutus, the risk of another bloodbath is never far away.