The authorities in Malawi say at least 170 people have died in flash floods – a sharp rise on previous figures.
Heavy rain over the past month has swept many houses away and caused residents to flee to higher ground, some crossing the border to Mozambique.
Vice-President Saulos Chilima said more than 100,000 people had been displaced from their homes, mostly in the south.
Earlier this week, the government declared a third of the country to be a disaster zone and appealed for help.
Humanitarian relief is slowly arriving in the district of Chikwawa, where the waters have started to recede. But some of the most affected areas downstream are only accessible by helicopter, making humanitarian intervention difficult. Doctors Without Borders/Médecins Sans Frontières (MSF), which has been responding to the floods since January 9, is refocusing its intervention around the town of Nsanje, where it has a long-standing regular project, and is assessing ways to access the more remote East Bank.
In Mozambique, overland travel from the north to the centre and south has become impossible after two bridges collapsed on the EN1 highway, reports the BBC’s Jose Tembe from the capital, Maputo.
As the rains have eased in the past few days, the water levels are expected to progressively come down. However, long-term solutions need to be found for people whose possessions and crops, which are the primary means of subsistence for 85 percent of the population in this region, have been completely destroyed in the flood.
“Delayed and overall below-average cumulative rains since the start of the rainy season in October last year have adversely affected the 2015 cereal crops, but prolonged heavy rains may worsen the situation,” said Jeffrey Luhanga, Principal Secretary in the Ministry of Agriculture.