Cyclone Batsirai, accompanied by strong winds and heavy rains, hit the Mananjari region of Madagascar.
This is the second storm to hit the island in weeks, a local meteorologist told AFP.
“I confirm that Batsirai hit Mananjari around 20:00 local time” (17:00 GMT), the AFP meteorologist was quoted as saying.
In late January, Tropical Storm Anna made landfall in Madagascar, then invaded Mozambique and Malawi. The death toll rose to 70 as emergency crews struggled to repair damaged infrastructure and help tens of thousands of victims.
The remnants of the storm passed over Zimbabwe, but no fatalities were reported there.
Tens of thousands of houses were destroyed. Some of them collapsed from the pouring rain and buried their victims under the rubble.
Bridges were washed away by flooding rivers, and livestock drowned and flooded fields, destroying the livelihoods of families in the villages.
In Madagascar, 110,000 people have been forced to leave their homes. In the capital, Antananarivo, schools and gyms have been turned into shelters.
In recent years, South Africa and especially Mozambique have been hit by devastating storms.