Emergency workers scrambled to rescue survivors on Monday from the wreckage of homes, hospitals, schools and businesses in Mayotte, a French archipelago in the Indian Ocean that was devastated by Tropical Cyclone Chido over the weekend.

At least 14 people were killed and more than 250 were injured in Mayotte, France’s poorest territory, according to preliminary figures, as French news outlets described “an unrecognizable island” and officials warned of an impending humanitarian catastrophe.

There were fears that the actual death toll could be far higher. “I think that there will be several hundred” deaths, François-Xavier Bieuville, France’s top-ranking representative on the archipelago, told a local news channel.

“Maybe we will be closer to a thousand, maybe several thousand,” added Mr. Bieuville.

France’s interior minister, Bruno Retailleau, said from Mayotte’s main island on Monday that it would take days to establish a death toll. President Emmanuel Macron has convened an emergency meeting for Monday evening.

Chido was the worst storm to hit Mayotte in 90 years, according to forecasters, who said that wind gusts exceeded 124 miles per hour.

The storm also killed at least three people in Mozambique, according to an early estimate of the death toll, local officials told the French news agency Agence France-Presse.