Image source, Reuters

This is what we know so far about what is believed to be the most destructive storm to hit Mayotte in 90 years:

• Hundreds of people are feared dead after the devastating Cyclone Chido wreaked a trail of devastation on the French island territory of Mayotte in the Indian Ocean
• People are starting to die of hunger and thirst, according to a Mayotte senator, because of the damage caused to the its infrastructure
• Entire settlements were flattened in wind speeds of more than 225km/h (140mph), with the poorest people living in shanty towns particularly hard hit
• Rescuers are searching for survivors and struggling to restore phone lines, power and water supplies

• France is pledging its support for the island and mobilising a huge relief effort

There have long been representatives of humanitarian organisation Medicins du Monde stationed in Mayotte, but following the destruction of Cyclone Chido team co-ordinators are now unable to reach some of them, the president of the organisation says.

"We are still very confused about what is going on for our friends in the field, it's a huge emergency," Jean-François Corty tells BBC News.

He adds that there was an outbreak of cholera there earlier this year, and there is a real risk of an epidemic of the water-borne disease emerging once again as people struggle to access clean water.

We are seeing images now of the French military on the ground in Mayotte, clearing debris, sharing information with residents and sorting through emergency aid.

As we've been hearing today, the cyclone caused significant damage to water, electrical and communication infrastructure, as well as to hospitals and roads - and it's unlikely we'll know the full human toll of the disaster for days.

Image source, Reuters

Image source, Reuters

Image source, Reuters

"The emergency is food aid because people don't have drinking water," a resident of Mayotte's capital, Mamoudzou, has told BFM TV.

The man, named as John by the French broadcaster, says some homes in his area still have electricity but that it risks being cut off this afternoon.

But he says people where he lives are helping each other while waiting for rescue teams to arrive.

BBC Weather presenter Sarah Keith-Lucas explains why Cyclone Chido has been so devastating for the French island of Mayotte and parts of south-east Africa.

Watch below:

Chido has passed beyond Mayotte, but is continuing its trajectory after making landfall in Mozambique.

The storm has been downgraded to a "depression", with winds speeds of around 48km/h (30 mph) and intense downpours expected.

French Interior Minister Bruno Retailleau is beginning an official visit to the French territory of Mayotte, where he is being briefed on the impact of Cyclone Chido.

France is trying to mobilise a humanitarian relief effort, with residents facing shortages of food and water in 31C heat.

The main hospital and other health centres are damaged or out-of-action, and communications remain difficult.

Image source, Police Nationale

The mayor of Mayotte's capital Mamoudzou, Ambdilwahedou Soumaila, says Cyclone Chido "spared nothing".

"The hospital is hit, the schools are hit. Houses are totally devastated," he tells the AFP news agency.

Mayotte prefect Francois-Xavier Bieuville earlier suggested to broadcaster Mayotte la Premiere that the eventual death toll could reach "several hundred, perhaps we will come close to a thousand or even several thousand".

People are "starting to die of thirst and hunger" in Mayotte, a senator for the territory tells a French broadcaster.

Speaking from a school that has been converted into a shelter on the island, Salama Ramia tells BFM TV: "There are sick people. People are sleeping on the ground."

The website for the Prefect of Mayotte said yesterday that work was under way to identify and repair damage to the water and electricity supply on the island.

Some context: Officials said last year that the territory was undergoing a significant drought. A journalist who covers the island also told the BBC's World Service earlier today it was already facing a "water crisis".

Earlier, we reported on comments from a resident in Mayotte's capital, Mamoudzou, who said they had been without water for three days.

Image source, Reuters

Around 75% of the people in Mayotte live below the French poverty line, with the rate of unemployment at about one in three.

At least a third of the territory's 320,000 residents live in shantytowns, where homes with sheet-metal roofs were flattened by the storm, according to the AFP news agency.

The population includes undocumented migrants who have travelled to the French territory in an effort to claim asylum, and they are thought to have been particularly hard hit due to the vulnerable nature of their housing.

We are starting to see more images now taken over the weekend of the destruction brought by Cyclone Chido and the subsequent clean-up efforts.

The BBC's Richard Kagoe, reporting from Nairobi, earlier said it was a "struggle" for rescue teams to find survivors due to the damage to roads and communications following the cyclone.

Image source, Gendarmerie Nationale

Image source, Reuters: Mohamed Ismael

Image source, Reuters: Mohamed Ismael

Rescue workers are struggling to reach some areas of Mayotte today as damage impedes access some parts of the islands.

French civil security spokesperson Alexandre Jouassard says "the next minutes and hours are very important".

"We are used to working in these conditions, and a few days after, you have pockets of survivors," he tells broadcaster France 2.

Image source, Gendarmerie Nationale

Sarah Keith-Lucas
BBC Weather

The specific impact of climate change on Cyclone Chido will be studied by scientists over the coming weeks, but there are some trends in global cyclone activity that show a clear link to human-induced climate change.

Although the overall number of cyclones has remained unchanged (or even decreased slightly) over recent decades, a higher number of these storms are reaching a more intense status, equivalent of a major category three hurricane or stronger.

Warmer air can hold more water, so the amount of rain that fell with Chido - especially during its time over land - is likely to have been enhanced by climate change.

For every 1C of warming, the atmosphere can hold 7% more moisture, so in storms such as Chido, rainfall is expected to be at least 7% heavier than it would be in a world without climate change.

The sea surface temperature in the Mozambique channel is currently around 1.5C warmer than average. Warmer waters in the oceans hold more energy, so it follows that these storms may well become more energetic with time and be able to unleash even more rainfall.

Rapid intensification of cyclones is also more likely with higher sea temperatures and so the fact that this storm strengthened so quickly may have been partly due to climate change.

Image source, Unicef/APTN

Cyclone Chido also made landfall in Mozambique, where it uprooted trees, damaged buildings and brought flash flooding about 25 miles (40km) south of the northern city of Pemba.

Three deaths have been reported.

The cyclone caused structural damage and power outages in the northern coastal provinces of Nampula and Cabo Delgado on Saturday morning, according to local authorities.

"Many houses were destroyed or seriously damaged, and healthcare facilities and schools are out of action," says Guy Taylor, a spokesperson for aid agency Unicef in Mozambique.

Taylor says Unicef was concerned about "loss of access to critical services", including medical treatment, clean water and sanitation, and also "the spread of diseases like cholera and malaria".

Image source, Getty Images

The central hospital in Mayotte has suffered significant damage, French Health Minister Geneviève Darrieussecq says.

"The health system is seriously affected and access to care has been seriously degraded. The Mayotte hospital centre has suffered significant material damage," Darrieussecq says in an update posted to social media.

In separate remarks to broadcaster France 2, she specifies that the damage includes "major water damage and destruction, notably in the surgical, intensive care, maternity and emergency units".

Mobile medical services are being set up, Darrieussecq adds.

That's how Mathilde Hangard describes the current situation in Mayotte. She's a journalist with Le Journal de Mayotte – she lives and works on the island, but was speaking to the BBC World Service's Newsday programme from Paris.

The island was already dealing with social problems including a "water crisis" when the cyclone hit, she says, describing how around half the population is under 17.

She says it's very difficult to calculate the number of victims because many who live in the island's slums bury their dead within 24 hours "for religious reasons".

“It’s another day in hell, without water, without electricity, without network. The island is cut off from the world. Everything is destroyed, the airport, the hospital, schools" she says.

“Entire slums have been razed. It’s horrible," she says.

Image source, Getty Images

Sarah Keith-Lucas
BBC Weather

After clearing away from Mayotte, Cyclone Chido continued its path westwards, and made its third landfall on Sunday just south of Pemba in Mozambique at 08:00 local time (06:00 GMT).

Although it had weakened slightly, it was still a major cyclone, with a well-defined eye, and winds above 200km/h (124 mph).

The storm then continued to advance inland through Mozambique and Malawi.

As it now moves over land, the winds are weakening rapidly, and the storm has been on downgraded to a "depression".

The winds are around 48km/h (30 mph), but the main threat is now the rainfall.

Intense downpours are expected to lead to flooding and landslides as the system moves in a south-west direction.

During Monday, it will cross southern Malawi, then Mozambique’s Tete province, before heading towards Zimbabwe overnight into Tuesday.

In the path of the storm, there could be 150-300mm of rain by the end of Tuesday.

Image source, Getty Images

The situation on Mayotte is "chaotic", according to Eric Sam Vah from the French Red Cross.

He's based on the French island of Réunion - on the opposite side of Madagascar to Mayotte - and has been speaking to BBC Radio 4's Today programme.

He says he's been receiving reports from French Red Cross volunteers on Mayotte. They have around 200 people on the ground there, he says, but they have only been able to reach around 20 of them.

Most of their volunteers, he says, have been “personally affected”.

“We still have limited information because of the difficulty of communication," Sam Vah says, adding the French authorities sent the first aid to the island over the weekend and more support is expected.

Around 100,000 on the island live in slums, he says.

“Most of the slums have been totally destroyed. And we haven’t received any report of displaced people. So the reality could be terrible in the coming days," he says.

Richard Kagoe
BBC News, Nairobi

Image source, Getty Images

It's a struggle for the rescue teams in Mayotte who have begun the search for possible survivors following the devastating cyclone over the weekend.

So far, France has deployed 110 soldiers, with an additional 160 expected to arrive later today when the French interior minister visits.

But it’s difficult because the search operation has been hampered by damage to the infrastructure across the island.

Moving around is also hard as the roads have been damaged, the power lines are down, and communication has been cut.

It's a very desperate situation.

A resident of Mayotte's capital Mamoudzou tells of his terror as cyclone Chido made landfall on Saturday.

John Balloz, a 39-year-old musician and composer, is from Comoros in East Africa, and is seeking asylum in Mayotte, according to the Reuters new agency.

We've translated his comments in the clip below: