At least seven people have been killed and thousands have fled their homes as Cyclone Jokwe continues to hit northern Mozambique, state radio reports.
Some 500 buildings including schools and hospitals, have been destroyed and electricity pylons downed.
The cyclone is expected to move south on Monday and people have been warned to stay out of the sea, as wind speeds reach 200km/h (125mph).
Tens of thousands of people were left homeless by flooding earlier this year.
Last month Cyclone Ivan battered parts of Madagascar, off the coast from Mozambique, but lost intensity before it reached the mainland.
Three of the deaths came when a wall collapsed at a mosque, while a fourth person was killed by a falling tree.
Northern Nampula province is worst-hit, including historic Mozambique Island.
Mozambican weather authorities have also issued a red alert for the coastal district of Pebane in central Zambezia province.
Paulo Zucula, director of Mozambique's National Institute of Disaster Management (INGC), told Reuters news agency that the situation in central areas already hit by flooding could be worsened as the storm moved south.
"The situation is terrible right now with dangerous winds of 200 km/h travelling to the southern parts of Mozambique," he said.
Meteorologist Mussa Mustafa warned people not to seek shelter under trees or in houses, whose roofs could be blown off.
He said the wind had whipped up seven-metre high waves in the Indian Ocean.