Tropical storm Ana has killed at least 46 people across Madagascar, Mozambique and Malawi.
The latest report from Madagascar's disaster management agency on Tuesday showed that 39 people have died and nearly 65,000 have been left homeless since last week.
"We are in the process of evacuating people from flooded areas," John Razafimandimby, rescue unit director in the disaster management agency, told AFP News Agency.
Meanwhile, Mozambican officials said three people were killed, with at least 66 others injured.
More than 3,800 people have so far been affected while a clinic and 16 school classrooms were destroyed overnight, according to the National Institute for Disaster Risk Management (INGC).
Ana also partially destroyed 546 homes and completely destroyed another 115 in Mozambique, the INGC said in a statement.
Four people also died in neighbouring Malawi, where the storm plunged most parts of the country into darkness overnight after flash floods raised the water levels, forcing the electric company to shut down its generators.
Heavy rains, mudslides
The storm, which formed over the east coast of Africa's largest island Madagascar on Monday, has brought heavy rains causing flooding and mudslides in the capital Antananarivo.
Several low-lying districts of the Antananarivo remain under high alert and emergency evacuations were launched overnight.
Government and UN agencies estimate that 500,000 people may be impacted in Mozambique's Nampula, Zambezia and Sofala provinces.
In an update on Tuesday morning, Malawi's power utility Electricity Generation Company said it was starting to restore power generation.