Survivors of Cyclone Freddy clung to dwindling hopes of finding missing relatives on Tuesday after the storm slammed into Malawi for its second strike on Africa in a record-setting rampage.

Ninety-nine people have died in the impoverished country since Freddy smashed into southern Africa at the weekend, just weeks after it made a deadly hit in late February, according to a provisional toll.

Many have died in mudslides that have washed away makeshift homes in the country's commercial capital, Blantyre.

Despair settled on Chilobwe, a township on the city's outskirts that accounts for around half of the victims.

Drenched in rains that have been falling for days, survivors milled about in disbelief, looking at flattened houses and structures.

Many believed there were still people trapped underneath the muddy rubble of earthen bricks -- but there were no rescuers in sight.

John Witman, in his 80s, in a raincoat and woollen hat, with his 10 family members in tow, stood in front of what was his son-in-law's house. There were just rocks left and gushing water, for the house had been washed away.

"I wish that we could find him, and find closure. We feel helpless because no one is here to help us -- we don't know what to do," he told AFP.

In Chimkwankhunda, a district a few kilometres (miles) away, Steve Panganani Matera, wearing a high-visibility green jacket, pointed to a mound of mud.

"There were plenty of houses, but they are all gone," said Matera.

"There are plenty of bodies down there in the mud, plenty of bodies."

- Deadly loop -

Cyclone Freddy reached landlocked Malawi early on Monday morning after sweeping through Mozambique at the weekend.

The storm last week broke an unofficial benchmark as the longest-lasting tropical cyclone on record, the UN's World Meteorological Organization (WMO) said on Friday.

The confirmed record belongs to a 31-day storm in 1994 named John.

Freddy brewed off weeks ago off the north Australian coast, becoming a named storm on February 6.

It crossed the entire southern Indian Ocean and made landfall in Madagascar on February 21, traversing the island before reaching Mozambique on February 24 , claiming nearly two dozen lives in both countries and affecting nearly 400,000 people.

It then returned to the Indian Ocean, refuelled on the warmth of its waters, and came back much more powerful at the weekend.

Meteorologists say that cyclones that track across the entire Indian Ocean are very infrequent -- the last such occurrences were in 2000 -- and Freddy's loopback is even more exceptional.

"It's a very rare thing that these cyclones feed themselves over and over again," said climate change expert and professor Coleen Vogel at South Africa's University of the Witwatersrand.

"People aren't expecting them to come back again once they've hit already".

"Climate change is starting to show impacts over these systems," Vogel said, adding however that more research was needed to say this with greater certainty.

More than 11,000 people were affected by the storm in Malawi, according to the UN.

The cyclone has piled more woes on a country grappling with the deadliest cholera outbreak in its history, which has killed over 1,600 people since last year.