Hurricane Irma has torn off roofs and knocked out all electricity on the French islands of Saint Martin and Saint Barthelemy in the Caribbean.

France has requisitioned planes and sent in emergency food and water rations.

The regional authority for Guadeloupe and neighbouring islands said that the fire station in Saint Barthelemy is under 3ft of water and no rescue vehicles can move.

The different categories of hurricane and the damage they can causeThe different categories of hurricane and the damage they can cause (PA Graphics)

It said the government headquarters in Saint Martin have been partially destroyed and the island is in a total blackout.

Electricity is also partially down on the larger island of Guadeloupe, where the threat receded despite danger of heavy flooding.

French minister for overseas territories Annick Girardin expressed fear “for a certain number of our compatriots who unfortunately didn’t want to listen to the protection measures and go to more secure sites”.

She added: “We’re preparing for the worst.”

Heavy rain and howling winds earlier raked the neighbouring island of Antigua, sending debris flying as people huddled in their homes or government shelters.

Officials warned people to seek protection from Irma’s “onslaught” in a statement that closed with “May God protect us all”.

In Barbuda, the storm ripped the roof off the island’s police station forcing officers to seek refuge in the nearby fire station and at the community centre that served as an official shelter. The Category 5 storm also knocked out communication between islands.

Midcie Francis of the National Office of Disaster Services confirmed there was damage to several homes but said it was too early to assess the extent of damage.

The storm had maximum sustained winds of 185mph, according to the Hurricane Centre. It said winds would fluctuate slightly, but the storm would remain at Category 4 or 5 strength for the next day or two.

The most dangerous winds, usually nearest to the eye, were forecast to pass near the northern Virgin Islands and near or just north of Puerto Rico on Wednesday.

“I hear it’s a Cat 5 now and I’m terrified,” Antigua resident Carol Joseph said as she finished her last trip to the supermarket before seeking shelter. “I had to come back for more batteries because I don’t know how long the current will be off.”

On the 108-square-mile island, people who live in low-lying areas were staying with friends and relatives on higher ground or sleeping in churches, schools and community facilities built to withstand hurricanes. None of the shelters had yet been tested by Category 5 winds, however.

Many homes in Antigua and Barbuda are not built on concrete foundations or have poorly constructed wooden roofs.

President Donald Trump declared emergencies in Florida, Puerto Rico and the US Virgin Islands, and authorities in the Bahamas said they would evacuate six southern islands.

The northern Leeward Islands were expected to see normal tide levels rise by as much as 11ft while the Turks and Caicos Islands and south-eastern Bahamas could see a surge of 20ft and higher waves later in the week, forecasters said.

Bahamas Prime Minister Hubert Minnis said his government was evacuating six islands in the south because authorities would not be able to help anyone caught in the “potentially catastrophic” wind, flooding and storm surge. People there would be flown to Nassau in what he called the largest storm evacuation in the country’s history.

“The price you may pay for not evacuating is your life or serious physical harm,” Mr Minnis said.

The US National Weather Service said Puerto Rico had not seen a hurricane of Irma’s magnitude since Hurricane San Felipe in 1928, which killed a total of 2,748 people in Guadeloupe, Puerto Rico and Florida.