Rescuers were racing against time Monday to reach survivors after a powerful cyclone hit the French Indian Ocean territory of Mayotte, laying to waste the territory's many shantytowns.
Cyclone Chido caused major damage to Mayotte's airport and cut off electricity, water and communication links when it barrelled down on France's poorest territory on Saturday.
Prefect Francois-Xavier Bieuville expects the final death toll will reach "close to a thousand or even several thousand", he told broadcaster Mayotte la Premiere.
The mayor of Mayotte's capital Mamoudzou, Ambdilwahedou Soumaila, told AFP the storm "spared nothing".
"The hospital is hit, the schools are hit. Houses are totally devastated," he said.
France's Interior Minister Bruno Retailleau will travel to Mayotte on Monday, his office said, with 160 soldiers and firefighters to reinforce the 110 already deployed.
Chido was packing winds of at least 226 kilometres (140 miles) per hour when it slammed into Mayotte, which lies to the east of Mozambique.
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.
One resident, Ibrahim, told AFP of "apocalyptic scenes" as he made his way through the main island, having to clear blocked roads himself.
As authorities assessed the scale of the disaster, a first aid plane reached Mayotte on Sunday.
It carried three tonnes of medical supplies, blood for transfusions and 17 medical staff, according to authorities in La Reunion.
Another French Indian Ocean territory, about 1,400 kilometres away, La Reunion is serving as a logistics base for the rescue operation.
Patrice Latron, prefect of Reunion, said residents of Mayotte were facing "an extremely chaotic situation, immense destruction".
Two military aircraft are expected to follow the initial aid flight, while a navy patrol ship was also due to depart La Reunion.
International pledges of supportThere have been international pledges to help Mayotte, including from the regional Red Cross organisation PIROI.
European Union chief Ursula von der Leyen said the bloc is "ready to provide support in the days to come".
The head of the World Health Organization, Tedros Adhanom Ghebreyesus, meanwhile said the body "stands ready to support communities in need of essential health care".
With around 100,000 people estimated to live clandestinely on Mayotte, according to France's interior ministry, establishing how many people have been affected by the cyclone is proving difficult.
Ousseni Balahachi, a former nurse, said some people did not dare venture out to seek assistance, "fearing it would be a trap" designed to remove them from Mayotte.
Many had stayed put "until the last minute" when it proved too late to escape the cyclone, she added.
Chido blasted across the Indian Ocean and made landfall in Mozambique on Sunday, where officials said the death toll stood at three.
"Many homes, schools and health facilities have been partially or completely destroyed," the United Nations children's agency UNICEF said.
The UN humanitarian agency, OCHA, warned 1.7 million people were in danger and the remnants of the cyclone could also dump "significant rainfall" on Malawi through Monday.
Zimbabwe and Zambia could also expect heavy rains, it added.
Chido is the latest in a string of storms worldwide fuelled by climate change, according to experts.
The "exceptional" cyclone was super-charged by particularly warm Indian Ocean waters, meteorologist Francois Gourand of the Meteo France weather service told AFP.