France is rushing help by ship and military aircraft to its poor overseas territory of Mayotte in the Indian Ocean that has been shattered by its worst storm in nearly a century.

Mayotte Prefect Francois-Xavier Bieuville told broadcaster Mayotte La 1ere that there might be several hundreds of deaths, “maybe we would approach a thousand.” He stressed that the counting of the human toll was difficult.

At least 11 people were killed after a cyclone slammed into Mayotte, the most intense storm to hit the French Indian Ocean archipelago north of Madagascar in nearly a century, French weather forecasters and authorities said on Sunday.