The death toll from Tropical Cyclone Freddy has passed 300 people, with authorities in Mozambique taking several days to assess the extent of the damage and loss of life.
The storm tore through southern Africa over the weekend for a second time after first making landfall in late February.
It is one of the long-lasting tropical cyclones ever recorded and one of the deadliest in Africa in recent years.
At least 53 people have died in Mozambique’s Zambezia province, authorities said late on Wednesday, more than doubling their previous count.
The toll is expected to continue to rise, said UN children’s agency UNICEF.
Malawi has reported 225 dead so far, with hundreds more injured and some still missing.
The storm killed about 27 people in Madagascar and Mozambique before lashing Mozambique a second time.
Continued rain and power outages have hampered search and rescue efforts this week as the storm caused severe flooding, swept away roads, and left bodies and houses buried in mud.
In the southern Malawi village of Mtauchira, six men carried a coffin down a dirt road that had turned into a river, slipping in the mud as the rain continued to fall.
Others stood in newly dug graves that had filled up like pools, scooping the water out with buckets so they could lower in the caskets.
Nearby, relatives of the dead cried and held each other, some holding umbrellas while others were drenched.
Malawi President Lazarus Chakwera has declared 14 days of national mourning and called for international support for relief efforts.
He said more than 80,000 people were displaced.
While electricity was starting to come back in Malawi on Thursday, many places affected by the storm had not had running water for a week, including the second-biggest city, Blantyre.