More rain is forecast for northern Mozambique, where the death toll from Cyclone Kenneth jumped to 38 on Monday.
Flooding and pounding rains hampered efforts to deliver aid to badly hit communities several days after the storm.
And more flooding is expected in the north-eastern port city of Pemba and surrounds.
An estimated 160,000 people are at risk from the second powerful cyclone to hit the southern African nation in six weeks, officials said.
It was the first time in recorded history that Mozambique had been hit by two cyclones in one season.
Heavy rain after Cyclone Kenneth has raised fears of a similar situation to last month, when more than 600 died in flooding in the days following Cyclone Idai.
Kenneth made landfall on Thursday with the force of a Category 4 cyclone.
Flooding was “critical” in parts of the country’s northernmost province of Cabo Delgado, including Ibo Island and the districts of Macomia and Quissanga.
In those areas, more than 35,000 buildings and homes had been partly or completely destroyed, the government said.
Mozambique’s national weather service on Monday afternoon forecast continued rain in the area.
The weather bureau said the north-eastern region would continue to receive moderate to strong rain of more than 50 millilitres over the next 24 hours.
Aid workers have told of “total devastation” affecting a 60-kilometre stretch of coastline and nearby islands.
The rising water has made many roads impassable and prevented air rescuers from reaching communities outside the region’s main city, Pemba.
Authorities were preparing for a possible cholera outbreak as some wells were contaminated and drinking water became a growing concern.
The heavy rain in Pemba caused deadly mudslides. Residents of one poor neighbourhood dug for bodies on Monday after two houses were crushed by the collapse of a sprawling dumpsite overnight, resident Manuel Joachim said.
A woman’s body had been found, Mr Joachim said. Later, the searchers discovered two hands sticking out from the mud and debris. They tied a rope to one of the hands to pull the body out but the rain started pouring again.
Five people were thought to be buried there, Mr Joachim said.
In other parts of Pemba, some tried to return to a semblance of daily life amid the destruction.
At a school, children in blue uniforms trooped into classes. Traders put their wares on street pavements and wooden tables while others were busy removing rubble from homes and yards.
