The death toll from floods that have battered South Africa climbed above 440 on Sunday as abating rains allowed rescue operations to accelerate after one of the deadliest storms in living memory.

Torrential rains that started lashing the southeastern coastal region last weekend quickly triggered heavy floods and landslides that smashed into Durban city and surrounding areas, pulling with them buildings and people.

By Sunday 443 people, including two police emergency workers, had died from the raging floods.

Scientists warn that floods and other extreme weather events are becoming more powerful and frequent as the world gets warmer because of climate change.

At least 63 other people are still missing and feared dead after the floodwaters -- the strongest to have struck KwaZulu-Natal in recent memory -- engulfed the region, trashing the idyllic beaches with debris.

Map of South Africa, showing areas that had the most rainfall in recent days
Map of South Africa, showing areas that had the most rainfall in recent days AFP / Eléonore HUGHES

Amid the destruction, climbing temperatures and an overcast sky, survivors sought divine solace and temporary distraction from their misery while observing Easter Sunday.

Thulisile Mkhabela went to church, at a large white concrete building with a tiled roof ceiling -- one of a few solid structures left standing by the raging floods that engulfed her Inanda township.

She recalled watching her house gradually collapse under the weight of the waters six days ago.

A man tries to collect plastic bottles amid debris at the Blue Lagoon beach after days of flooding in the coastal city of Durban which has left almost 400 people dead and tens of thousands homeless
A man tries to collect plastic bottles amid debris at the Blue Lagoon beach after days of flooding in the coastal city of Durban which has left almost 400 people dead and tens of thousands homeless AFP / RAJESH JANTILAL

It started with the living room. "We took out whatever we could," she said, and took the children to what was thought to be a secure outbuilding.

As "soon as we took them out then the bedroom started collapsing", she said.

The family then moved to an outbuilding, which had also been damaged but held together for the rest of the night.

That building has since collapsed and they are now "squatting" in her brother's two-bedroom house where 12 people are crammed.

Worshippers at the United Congregational Church of Southern Africa raised hands as tears rolled down, while others fell to the ground during emotional prayers.

Rains were starting to let up in the flood-ravaged east, allowing for search and relief aid operations to continue after one of the deadliest storms in living memory
Rains were starting to let up in the flood-ravaged east, allowing for search and relief aid operations to continue after one of the deadliest storms in living memory AFP / RAJESH JANTILAL

"The loss of life, destruction of homes, the damage to the physical infrastructure... make this natural disaster one of the worst ever in recorded history of our province," said Sihle Zikalala, the premier of the KwaZulu-Natal province.

Rains were starting to let up on Sunday, allowing for search and relief aid operations to continue in and around Durban.

The city of 3.5 million was overcast but the South African Weather Service said rainfall would have cleared by midweek.

But recovery operations and humanitarian relief continued in the economic hub and tourist magnet city, whose beaches and warm Indian Ocean waters would normally have been teeming with Easter holidaymakers.

The government, churches and charities were marshalling relief aid for the more than 40,000 people left homeless by the raging floodwaters.

The government has announced an immediate one billion rand ($68 million) in emergency relief funding.

Deputy Social Development Minister Hendrietta Bogopane-Zulu said some 340 social workers had been deployed to offer support to traumatised survivors, with many still missing children and other relatives.

Most casualties were in Durban, a port city and a major economic hub.

Parts of the city have been without water since Monday after floods ripped away infrastructure.

Scores of hospitals and more than 500 schools have been destroyed.

The intensity of the floods took South Africa, the most economically advanced African country, by surprise.

While the southeastern region has suffered some flooding before, the devastation has never been so severe. South Africans have previously watched similar tragedies hit neighbouring countries such as cyclone-prone Mozambique.