Video report by ITV News reporter Faye Barker
Fears are growing that the humanitarian crisis in Mozambique, Zimbabwe and Malawi could further intensify, with torrential rains in the region expected to continue into Thursday, and flood waters set to rise.
As well as the immediate threat caused by flooding, hunger and illness are growing concerns, with crops destroyed and waterborne diseases likely to spread.
More than 1,000 people are feared to have been killed after Cyclone Idai hit the three countries last week.
"Floodwaters are predicted to rise significantly in the coming days and 350,000 people are at risk," the United Nations have said.
Hundreds of people are known to have died, with thousands still missing.
Mozambican officials said at least 200 people had died in their country, but the country's President, Filipe Nyusi, said he feared as many as 1,000 people could have been killed.
In neighbouring Zimbabwe as many as 350 people may have died.
Cyclone Idai has been described as one of the most destructive storms and the worst flooding in the region in decades.
The World Food Programme (WFP) estimate that 1.7 million people were in the direct path of cyclone.
Tens of thousands of people have lost their homes and now seek help at the already under pressure evacuation centres.
Relief efforts that were initially stifled by airport closures have slowly gained pace, and foreign governments have begun pledging aid to help the region struck by the cyclone.
“Everyone is doubling, tripling, quadrupling whatever they were planning,” said Caroline Haga of the Red Cross in Beira, Mozambique, referring to supplies and aid workers.
“It’s much larger than anyone could ever anticipate.”
The European Union released 3.5 million euros (£3 million) in emergency aid, and the UK pledged up to £18 million.
Neighbouring Tanzania’s military airlifted 238 tons of food and medicine.
Matthew Pickard of the humanitarian organisation Care said the response to Idai has been similar to previous natural disasters.
Local authorities and international non-governmental organisations worked their way to the area in the first days, with additional aid destined to arrive soon after.
The slow-moving catastrophe of the flooding and the inability to access some of the hardest-hit areas has limited the ability of some to see the scale of the cyclone, but aid will spike as the details become clearer, Mr Pickard said.
Speaking from Mozambique, Sacha Myers of Save the Children said she was awaiting the arrival of a cargo plane carrying 51 tons of emergency supplies, but said getting them where they needed to go remained difficult as roads had been washed away or submerged.
Ms Myers told ITV News, Save the Children had deployed its emergency health unit, rapid response teams that come in to disaster zones.
One of their specialist areas is managing disease outbreaks.
"We're working with communities to tell them not to drink contaminated water, making sure they're washing their hands when they can to ensure they don't spread diseases like cholera," she said.
"There are large areas where people are really finding it difficult to find sources of clean water," said Gert Verdonck, the emergency coordinator with Doctors Without Borders in Beira.
"On top of all of that, there's the issue of how to treat people who fall sick with so many health centres damaged or destroyed," he added.
The United Nations is deploying resources too, deputy spokesman Farhan Haq said, but logistics remained challenging and the hardest hit areas remained inaccessible.
Mozambique appears to have borne the brunt of the storm after making landfall in the Indian Ocean port city of Beira - leaving it 90% destroyed - on Thursday before lashing neighbouring Zimbabwe and Malawi.
Three days of national mourning have begun in Zimbabwe.
Also on Wednesday, Zimbabwe's President Emmerson Mnangagwa visited the hard-hit mountain community of Chimanimani on the eastern border with Mozambique where he told residents that aid was on its way an that he did "not want to hear that anyone has died of hunger".