The death toll from South Africa's floods has continued to rise, follows weeks of heavy rains that began in December. Seventy people have died and more than 8,000 families have been forced to leave their homes. Five other countries in the region, from Mozambique to Namibia, are on alert for further floods. Some of the biggest rivers in the region, the Zambezi and the Okavango, are at about twice their normal levels. South Africa has declared eight of its nine provinces disaster areas. Co-operative Government Minister Sicelo Shiceka said the flood damage was estimated at $51m (£32 million). At least 10 people have also died in floods in neighbouring Mozambique and more than 10,000 people have been evacuated from their homes. Relief workers fear a repeat of the kind of disaster that struck Mozambique in 2000, when massive floods killed 800 people. Botswana, Namibia, Zambia and Zimbabwe have also been affected by heavy rains, says Elizabeth Byrs, of the UN's Office for the Co-ordination of Humanitarian Affairs. The UN is warning that there is an increased risk of cholera, which is endemic in some countries. Meteorologists say southern Africa's floods are caused by a natural cycle called the El Nino Southern Oscillation (ENSO), which has also been linked to recent flooding in Australia and the Philippines.