Eight residents die at a Florida nursing home which has been without power since Hurricane Irma and the state governor vows a full investigation into what he calls an "unfathomable" event.

At least 10 people were killed after Hurricane Irma tore through Cuba over the weekend, authorities have said in a statement, bringing the death toll in the Caribbean from the ferocious storm to 38.

A massive but weakened Hurricane Irma zeroes in on the Tampa Bay region after hammering much of Florida with roof-ripping winds, gushing floodwaters and widespread power outages.

​Hurricane Irma regains strength as it begins pummeling Florida, lashing its southern island chain with hurricane-force wind gusts and threatening landfall within hours.

Hurricane Irma ripped through the Caribbean, leaving a trail of devastation and killing 17 as it barrelled towards the United States where up to a million people have been told to flee.

Hurricane Irma sowed a trail of deadly devastation through the Caribbean on Wednesday, reducing to rubble the tropical islands of Barbuda and St Martin and claiming at least seven lives.

Officials in Florida's Key West and popular Caribbean tourist islands order people to evacuate as Irma, a "potentially catastrophic" Category Five hurricane, was set to make landfall.