In Mozambique, flooding threatened the fertile farming land of the Limpopo Valley and regional capitals and waterborne disease loomed. Several major roads remained impassable in Botswana and Zimbabwe.
The downpours have caused the worst flooding seen in parts of the region for 50 years.
South African police warned that areas most affected by recent flooding would have to endure more rain and they expected the death toll to rise.
''The rain has started again. We have advised people to evacuate low-lying areas. Police and the army are helping in the evacuation,'' Northern Province police spokeswoman Ronel Otto told Reuters.
The province was the worst hit part of South Africa in last week's flooding which claimed the lives of at least 24 people.
Towns and villages around the Levubu River area and farm land in the Rooi Bokkraal areas were the most vulnerable to more flood waters, Otto said.
The South African Weather Bureau forecast thunderstorms and showers for the Northern Province at least until Friday.
In Mpumalanga province, the official death toll stood at 15 but this was expected to rise, a police spokesman said. Rain was forecast for the province until Thursday.
The rains have caused havoc across northern South Africa, leading to drownings and traffic chaos in the commercial capital of Johannesburg.
In neighbouring Mozambique, a huge flood wave hit the district of Chokwe at the weekend, damaging the fertile farmland of the Limpopo Valley in the southern province of Gaza.
On Sunday, the flood peak moved further downstream and hit the Chibuto district, cutting off villages including Malehice, which is the home village of President Joaquim Chissano.
State officials have hastily removed equipment from government buildings in the provincial capital Xai-Xai.
''If the river continues to rise, the waters can invade the city,'' said Adriano Chivango of the National Disaster Management Institute.
In flooded areas of Maputo province, an estimated 10,000 people were cut off from the rest of the country. Mozambique's main north-south highway through Manhica was impassable.
Mozambique has appealed to the international community for $2.7 million for emergency relief. Reut04:13 02-14-00
- Reuters - Thomson Reuters Foundation
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