Parts of Mozambique are already facing floods Image caption: Parts of Mozambique are already facing floods
BBC News, Maputo
More than 600,000 people in Mozambique could be affected by Cyclone Freddy, which is expected to make landfall in the coastal provinces this week, the authorities say.
The areas considered most at risk are the Zambezi valley, central regions and the southern Inhambane province.
At least 100,000 people will require state assistance should the cyclone hit at full strength, according to Agostinho Vilanculos, who heads the water resources department.
At a National Centre for Emergency Operations meeting, he described the tropical storm as an intense weather system with wind gusts of between 280km (174 miles) and 290km per hour.
In the coastal city of Beira, residents have been fortifying their homes with sandbags and placing metal sheets on windows as well as pruning trees in backyards.
They have also been stocking on food and water along with supplies of candles and lanterns.
BBC reporter in Madagascar
The authorities in Madagascar say that at least two million people will be affected once Cyclone Freddy makes landfall in the eastern part of the country.
Experts from the National Bureau of Risks and Catastrophes have predicted that it will hit nine regions in the country.
Emergency teams are preparing to deal with heavy rains, floods and even landslides in areas that will be affected.
The cyclone has been churning in the Indian Ocean for weeks and according to experts, its impact will be felt between the districts of Vatomandry in the south-east and Manakara on the east coast.
Those living in the areas have been advised to strengthen their doors and roofs, cut down dangerous trees and stay indoors during the tropical storm.
The island nation is among the top 10 African countries most exposed to cyclones and vulnerable to disasters, according to the World Food Programme,
When Cyclone Cheneso struck in January some 30 people died and more than 40,000 were forced from their homes.