The governor of the Turks and Caicos islands has told the BBC that people in low-lying areas have been moved into shelters as Hurricane Irma sweeps in.

John Freeman said extra flights had also been laid on to get as many tourists as possible to safety.

"Up until yesterday evening, when the airport closed, we had extra flights moving people out and so we've tried to diminish the numbers here, quite a number have gone to Jamaica," he said.

Irma is due to strike the islands in the next few hours.

Hurricane Jose, further east in the Atlantic Ocean, has become a major hurricane.

Pictures and video footage show the almost destroyed Caribbean island of St Martin, then and now.

Up to 26 million people could be affected by Hurricane Irma, the Red Cross has warned.

Walter Cotte, Americas director for the International Federation of Red Cross and Red Crescent Societies (IFRC), said their "worst fears" had already played out in Barbuda and elsewhere.

"People across the Caribbean will need our help to withstand and then recover from this storm," he said. "We're already preparing what could become a massive and multi-country response effort."

Mr Cotte said about 1.2 million people had already been "battered" by Irma and that millions more, particularly in the Dominican Republic, Haiti and Cuba, were at risk from destructive winds and torrential rain.

Footage from the National Oceanic and Atmospheric Administration (NOAA) shows fast winds and pounding rain inside Irma this morning.

French Prime Minister Edouard Philippe says about 50 people have been injured, two seriously, on St Martin and the nearby smaller island of St Barts.

He said officials were in the process of identifying the four people who died on St Martin, adding that no deaths were reported from St Barts.

Earlier, France lowered the death toll on St Martin from eight to four.

Image source, AFP

Above average ocean temperatures have helped trigger the conditions required to produce three simultaneous hurricanes - Irma, Katia, and Jose.

Nasa graphics show the above average ocean temperature.

Dr Virginia Clerveaux, director of the Turks and Caicos Department of Disaster Management and Emergencies, has told the BBC that they are expecting heavy rainfall and storm surges.

"Flooding will be a major concern for us, we are a low-lying country and very coastal and therefore a storm surge could possibly inundate inland areas," she said.

Many islanders remember the damage caused by Hurricane Ike nine years ago, Dr Clerveaux said, and Hurricane Irma poses an even greater threat.

"We are now trying to remind them that this is a category five [storm] and in the history of the Turks and Caicos islands this is the largest storm we have ever been threatened by."

The National Hurricane Center have said the Turks and Caicos Islands could face the worst of a possible storm surge.

Image source, EZE EGWUATU/Reuters

Social media users in Sint-Maarten are posting images of broken buildings and stormy seas.

The Netherlands says there is large-scale destruction and has sent a Hercules aircraft to deliver aid and extra military personnel.

Image source, EZE EGWUATU/Reuters

France has lowered the death toll in Saint-Martin from eight to four. That brings the overall death toll to nine.

Several US airlines have announced that they will cap prices on flights to or from Florida as well as other regions affected by Hurricane Irma.

American and JetBlue have set a maximum price of $99 (£75) for any flights.

Delta has also announced a cap, with a spokesperson saying they have been "examining and adjusting fares in Florida since early this week, when Irma's path became apparent and demand to fly out of the area surged".

The decision comes in response to accusations that the carriers were inflating prices artificially.

But market analysts believe that the steep costs were caused by computer algorithms that cause costs to go up as each plane nears maximum occupancy.

The US Coast Guard has begun conducting "overflight and port assessments" around Puerto Rico and the US Virgin Islands.

"Our first priority is ensuring safety of lives and helping anyone in distress," said Capt Eric King, who is leading the response team.

"One of the top priorities, second only to life saving operations, is working with partner agencies to conduct port and waterway assessments to determine the impacts to the maritime transportation system", he added.

The Governor of Puerto Rico, Ricardo Rosselló, has said at least three deaths are being attributed to Irma.

He said one woman was electrocuted, another suffered a fall while being transported to a shelter and a man died from injuries after his car crashed.

Mr Rosselló said the capital, San Juan, saw waves of up to 30ft (9m).

More than 6,000 Puerto Ricans are in shelters.

Photos just released by ABS-TV in Anguilla show a ruined airport hangar.

One Anguilla resident told the BBC the island looked as if it had been struck by a nuclear bomb, with roofs torn off many of the main buildings, including the hospital.

One death has been reported on the island.

The BBC's Paul Blake and Laura Bicker are in Puerto Rico and say the island has avoided the worst of the storm.

Our team has found lots of debris and some localised flooding around San Juan, but nothing as serious as the devastation found on the low lying islands of Barbuba and St Martins.

The Dutch Marines have tweeted images of the Princess Juliana International Airport, which they say is still unreachable.

The airport is famous for the adjacent beach, where sunbathers lounge beneath landing planes.