Tens of thousands of people in Mozambique are being rescued as rising waters continue to devastate the southern African nation - the worst flooding in a generation.

Teams from Brazil, South Africa and the UK have been helping with life-saving rescue operations.

"For me, this is the first time I have experienced a calamity of this magnitude. Elders say a similar disaster took place in the 1990s," 24-year-old mechanic Tomaz Antonio Mlau says.

Mlau and his family, who live near Marracuene - a town 30km (19 miles) north of the capital, Maputo - woke up to find their house inundated after the Inkomati River burst its banks.

"When a rescue boat came a few hours afterwards, we did not hesitate to board it and come to safety in Marracuene town," he said, adding they had to abandon all their belongings and only managed to bring a change of clothes.

Mlau, his wife and two children have found refuge at one of six centres - schools and churches - that are so far sheltering about 4,000 people.

Many of those gathered at Gwazamutini Secondary School are farmers from the low-lying areas with livestock and rice fields.

"We lost everything in the floodwaters, including houses, TV sets, fridges, clothing and livestock - cattle, goats and pigs. Our farms are under water. I am a farmer. I grow quality rice," 67-year-old Francisco Fernando Chivindzi told me.

His home is in Hobjana, one of several flooded neighbourhoods between the left bank of the Incomati River and the coastal tourism resort of Macaneta. Marracuene town is on the river's right bank.

"The floodwaters reached heights we weren't expecting. We have never experienced this level of flooding in my lifetime," Chivindzi said.

"We are happy to be here on higher ground. However, we are very worried that all our belongings were left behind."

The farmer expressed his gratitude to the boat owners who came to assist him and his neighbours free of charge - and he urged others to save themselves.

"We hear that there are still some people resisting - clinging to treetops and on roofs. I wish they would heed the rescuers and join us here in this temporary shelter. We should value life more than the goods," the father of nine said.

This was a view echoed by Shafee Sidat, the mayor of the Marracuene municipality, as he visited Gwazamutini Secondary School on Saturday.

"We still have people to rescue, some of whom refuse to abandon the risk areas. That's a challenge. We reckon that more than 10,000 people are affected in Marracuene as a whole," he told me.

At least 642,122 people have been affected since 7 January by flooding - particularly in southern and central regions, with 12 deaths recorded so far, according to provisional data from the National Institute for Disaster Risk Management and Reduction.

In total 125 people have died in Mozambique since the rainy season began in October.

Mayor Sidat fears the situation is likely to get worse because of heavy rain in neighbouring South Africa, the source of the Inkomati River.

"We are worried about discharges of a South African dam on the Inkomati River. Our town is the last one downstream," the mayor said.

"Before the waters flow into the Indian Ocean, they flood the 'machambas' (farmlands), homes and grazing areas here in the low-lying zones."

Some aerial views show water as far as the eye can see. Hundreds of families remain cut off.

All vehicles have now been banned from roads between the provinces of Maputo and Gaza to the north.

Transport Minister João Matlombe said it was because main roads, in particular the N1 highway which runs the whole length of the country and is the only link to the north, were flooded.

The suspension is already leading to shortages and price hikes, including of basic foodstuffs, coconut and fuel - even as far away as the north-western city of Tete, more than 1,500km from Maputo.

For those at shelters in Marracuene, food is also a challenge.

"There isn't yet enough food to eat," said Aninha Vicente Mivinga, whose two children are aged two and five.

"On the first day this Friday, there was almost nothing to eat. It was painful to see children sleeping without anything to eat, except biscuits. Today things improved," she said.

Mivinga, who is a police officer and farms in her spare time, described how she was at work in Marracuene town when the floods hit at her home in Hobjana.

The 32-year-old had taken the precaution of taking her children to stay with family members who lived on higher ground because of the continuous rain, but even they were affected by the rising waters.

"To learn that my children and other members of the family were on floodwaters and at risk of dying was horrific. I was devastated and completely shaken," the officer said.

"Eventually my relatives were brought to safety.

"It is the first time since I was born that we've been affected by flooding of this dimension."

Mivinga said that students were meant to resume classes soon - and she would like the authorities to find permanent alternative accommodation for them.

Hundreds of people are currently camping down in the classrooms using a traditional wrap cloth as bedding on which to lie down.

"When floodwaters subside, I believe everyone would love to go back home, but it's too risky. If only the authorities could give us another place on safer ground. We would go back to the risky area only for farming purposes but live on safer ground," the police officer said.

Education Minister Samaria Tovela has already hinted that the cabinet is to consider rescheduling the start of the 2026 academic year, originally planned to begin next week, "to allow flood victims to continue using them as accommodation centres, especially in the provinces of Maputo and Gaza, the most affected at the moment".

Chivindzi, who is not sure that the floodwaters will recede before schools resume, is determined to return home.

"We'll restart life from scratch," the farmer says.

Mlau, who is unable to get to the garage where he works, is less sure of the future and the risks of starting again in the same place.

"Even if waters subside, I am not sure I'll go back there."