JOHANNESBURG — A deadly cyclone that struck Mozambique and other countries in southern Africa has nearly obliterated the worst-affected areas, flooding vast stretches of land, destroying roads and dams, and cutting off victims from help.
The cyclone, called Idai, has affected more than 1.5 million people, with a death toll now in the dozens but feared to be far higher.
The storm destroyed “90 percent” of Beira, a city of about a half-million people that is Mozambique’s fourth largest and faces the Indian Ocean, the International Federation of Red Cross and Red Crescent Societies said on Monday.
The Red Cross and other aid organizations estimated the total number of deaths at 150, though they warned that the figure could rise as rescuers reached previously inaccessible areas. Mr. Nyusi said the death toll in Mozambique, which stood at 84, could climb to more than 1,000.
The storm landed in Beira late Thursday before moving inland into Malawi and Zimbabwe. Aerial images of the city showed houses surrounded by water. Aid officials reported widespread damage to homes, hospitals and schools. Many areas were left without electricity and telephone service.
“We’re starting to understand the magnitude of the impact on Beira,” said Euloge Ishimwe, a Red Cross spokesman, adding that Red Cross rescue workers had reached the city the day before.
Speaking on state radio after flying by helicopter over Beira and other affected areas, Mr. Nyusi said that overflowing rivers had submerged villages and isolated communities. He reported seeing floating bodies.
In Malawi, scores died from flash floods that preceded the cyclone. The violent weather continued into Zimbabwe as a tropical storm, causing damage with heavy rain and strong winds in the eastern provinces close to Mozambique.
Many people were missing, and were suspected of having been buried in mudslides.
In Chimanimani, Zimbabwe’s hardest-hit district, residents said they had been left marooned after the area’s infrastructure was destroyed.
Denis Chiwonde, a resident of Chimanimani, said floods had swept away houses, a bank and other buildings. Rocks and fallen trees had made many roads impassable. Power lines were down.
Many who had escaped from the floods took shelter at a local Catholic parish, he said.
“Chimanimani is down,” Mr. Chiwonde said.
Christopher Muteweri, the pastor of the Seventh-day Adventist Church in Chimanimani, said that eight of his congregants had died in the storm, and that some were missing.
“We believe they are trapped or they were washed away,” he said.
Mr. Muteweri said residents had been instructed over the news to evacuate to a local government office and “wait for helicopters there.”
At the St. Charles Lwanga School in Chimanimani, falling rock led to the collapse of a dormitory that housed sleeping pupils, said Jackson Muranganwa, a leader of the Catholic parish.
“There are high fears of loss of life,” he said. “Let’s pray.”
Maxwell Mapungwana, a teacher in Chimanimani, said floods had taken away his brother and his family as they slept in their home.
“We have up to this time not recovered their bodies,” he said.