Officials hoped to get rescue helicopters Sunday to the Save River Valley. The government estimated 17,000 people in the valley were in danger from water levels that reportedly rose several feet in a matter of hours.

Aid workers, hampered by washed-out bridges and roads everywhere, can't cope with the scale of the disaster. Three weeks after rains began drenching southern Africa - and four days after Cyclone Eline roared through - human tragedies are still unfolding.

"It's just reached a point that's incredible and it's going to get much worse," said Michelle Quintaglie,
spokeswoman for the U.N. World Food Program.

To the east, the Indian Ocean was brewing another tropical storm for Mozambique. To the west, swollen rivers in Zimbabwe and South Africa were expected to dump much of the overflow in downstream Mozambique by Monday.

In Zimbabwe, floodwaters Friday night shoved a bus carrying an unknown number of passengers off a bridge and into a raging river. No survivors were found Saturday, but rescuers did find six tourists missing from another bus that had stalled in floodwaters.

Lines of cars up to two miles long formed at gas stations in Zimbabwe, where flooding prevented trucks from bringing fuel to the landlocked nation. The official death toll in Zimbabwe was 29 and likely to climb.

In South Africa, parts of hard-hit Northern Province - where 76 people have died - were cut off from aid and communication, said National Defense Force Col. Flip le Roux.

"There must be far more people in danger than we know of," Le Roux told Cabinet ministers who flew over the province. Overflowing rivers had smashed bridges into pieces. Roads were converted into streams. Streams had become rivers.

In Malawi, a sliver of a country bordering Mozambique, storms have blown off roofs, downed power lines and trees and flattened crops. There were no reported fatalities.

The Mozambican government estimates that more than 200,000 people are homeless and at least 70 have died - a toll expected to rise sharply.

Aid workers who flew over the Save River Valley said they saw several thousand people in trees, on thatched roofs and huddled on narrow strips of land, apparently marooned by floodwaters since Monday.

"These people are very, very desperate. It must be a nightmare for them," said Carol Collins of the British charity Save the Children. "The water is moving very, very rapidly. I'm sure some of them were swept away."

Two pilots and World Food Program officials saw several bodies being swept along by the floodwaters. The international response to appeals by Mozambique's government and U.N. agencies for $65 million in aid was growing.

A U.S. Air Force plane carrying tents, blankets and other supplies, and an Italian aid plane were headed for Mozambique, as were two military helicopters from Malawi. The World Bank announced a $2.5 million grant for flood victims.

Five South African Air Force helicopters have already plucked more than 3,000 people to safety in southern Mozambique over the past two weeks, and were heading to the Save River, 620 miles north of Maputo, the capital.

Several trucks carrying emergency aid became stuck Friday in the rising flood waters near the town of Save. Only two buildings protruded from the muddy water in the town of Nova Mambone, where the Save River enters the sea.

The World Health Organization has warned that 800,000 are at risk from cholera, malaria and other diseases because of the floods.