Rescue workers and supplies are being rushed in by air and sea, but their efforts are likely to be hindered by damage to airports and electricity distribution in a territory where even clean drinking water was already subject to chronic shortages.

The toll of 14 was counted in a provisional list compiled by authorities, a security source told AFP.

Nine people were gravely wounded and fighting for their lives in hospital, said Ambdilwahedou Soumaila, mayor of Mayotte's capital Mamoudzou, while 246 more were seriously injured.

"The hospital is hit, the schools are hit. Houses are totally devastated," he said, adding that the hurricane "spared nothing".

Mayotte's 320,000 residents were ordered into lockdown as cyclone Chido bore down on the islands around 500 kilometres (310 miles) east of Mozambique.

Its gusts of at least 226 kilometres per hour had "completely destroyed" the territory's many shantytowns, acting Interior Minister Bruno Retailleau said following a crisis meeting in Paris late Saturday.

Electricity poles were hurled to the ground, trees uprooted and sheet-metal roofs and walls torn off improvised structures inhabited by at least one-third of the population.

"It will take several days" to establish the full death toll, but "we fear that it is heavy", Retailleau said, adding that the Muslim custom of burial within a day of a death could complicate the count.

Information from the locked-down population, in shock and largely cut off from water and electricity supplies, is slow to filter out, a source familiar with the recovery effort told AFP.

One local resident, Ibrahim, told AFP of "apocalyptic scenes" as he made his way through the main island, having to clear blocked roads for himself.

"Even the largest companies have suffered damage," he added.

- Scramble for supplies -

Retailleau will travel to Mayotte on Monday, his office said, alongside 160 soldiers and firefighters to reinforce the 110 already deployed to the islands from mainland France ahead of the storm.

Medical personnel and equipment were being delivered from Sunday by air and sea, said the prefecture in La Reunion, another French Indian Ocean territory some 1,400 kilometres away on the other side of Madagascar.

Pope Francis, visiting French Mediterranean island Corsica on Sunday, urged people to pray for Mayotte residents.

"Everything has been swept away, everything is razed," said Mounira, a woman whose house was destroyed in the Kaweni district in Mamoudzou's east -- France's largest shantytown.

More than 15,000 homes are without electricity, acting Environment Minister Agnes-Pannier Runacher has said, while telephone access is severely limited even for emergency calls.

Acting Transport Minister Francois Durovray wrote on X that the Pamandzi airport on Petite-Terre, the smaller of Mayotte's two major islands, had "suffered major damage".

- Storm hits Mozambique -

Just northwest of Mayotte, the Comoros islands, some of which had been on red alert since Friday, were also hit, but suffered only minor damage.

Cyclone Chido later slammed into Mozambique early Sunday, bringing gale-force winds and heavy rain when it made landfall around 40 kilometres (25 miles) south of the northern city of Pemba, weather services said.

"The cyclone is already affecting Pemba with a very strong intensity. We were monitoring the situation but there is no communication with Pemba since 7:00 am (0500 GMT)," National Institute of Meteorology director Aderito Aramuge told AFP.

UNICEF said it was on the ground to help the people impacted by the storm, which had already caused some damage.

"Many homes, schools and health facilities have been partially or completely destroyed and we are working closely with government to ensure continuity of essential basic services," it said in a statement.

Cyclone Chido is the latest in a string of storms worldwide to be fuelled by climate change, according to experts.

The "exceptional" cyclone was super-charged by particularly warm Indian Ocean waters, meteorologist Francois Gourand of France's Meteo France weather service told AFP.

The United Nations Office for the Coordination of Humanitarian Affairs (OCHA) said Friday it was similar in strength to cyclones Gombe in 2022 and Freddy in 2023, which killed more than 60 people and at least 86 in Mozambique respectively.

It warned that some 1.7 million people were in danger, and said the remnants of the cyclone could also dump "significant rainfall" on neighbouring Malawi through Monday, potentially triggering flash floods.

Zimbabwe and Zambia were also expected to see heavy rains, it added.

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