Fires, fuelled by the wind, have swept across the historic town of Lahaina, West Maui, leading to mass evacuations.

"Our main focus now is to save lives," Maui mayor Richard Bissen Jr said.

"The gravity of losing any life is tragic. As we grieve with their families, we offer prayers for comfort in this inconsolable time."

Acting governor Sylvia Luke has declared a state of emergency and has urged people not to travel to the island, describing it as "not a safe place to be".

As winds eased slightly, some aircraft resumed flights, enabling pilots to view the full scope of the devastation.

Aerial video from coastal Lahaina showed dozens of homes and businesses flattened, including in Front Street, where tourists gathered to shop and dine.

Smoking heaps of rubble lay piled high next to the waterfront, boats in the harbour were scorched, and grey smoke hovered over the leafless skeletons of charred trees.

More than 270 structures have been damaged or destroyed so far, according to officials in Lahaina.

The town dates back to the 1700s, was once the capital of Hawaii and the seat of Kamehameha III during its period as a kingdom in the 1800s, and has long been a favourite destination for tourists.

"It's horrifying. I've flown here 52 years and I've never seen anything come close to this," said Richard Olsten, a helicopter pilot for a tour company.

He said he went up in a helicopter to review the damage and see what help him and his team could provide to emergency crews.

"We were totally shocked at what we saw. We did not expect to see the extent of the destruction of Lahaina," he told Sky News.

Read more:
Portugal wildfires: Satellite image shows impact of blaze
Canada town evacuated as wildfire cross into US

"Basically, the whole Front Street of Lahaina, all the shops, the historical buildings, everything, has been burnt right to the ground.

"There are hundreds of people homeless, there's still no power in the whole town, people can't get access to food, so it was just an absolutely heart-wrenching site.

"And the really sad part about it too is the loss of the historical buildings on Front Street that can't be rebuilt - so that whole area is levelled to the ground."

British rockstar Mick Fleetwood, who has lived in Hawaii for decades, revealed his restaurant had been lost due to the blaze in a post on X, formerly known as Twitter.

The Fleetwood Mac drummer wrote: "Fleetwood's on Front Street has been lost and while we are heartbroken, our main priority is the safety of our dear staff and team members.

"On behalf of myself and my family, I share my heartfelt thoughts and prayers with the people of Maui."

US President Joe Biden offered his "deepest condolences" to the people of Hawaii - the country's 50th state.

"Our prayers are with those whose homes, businesses, and communities are destroyed," he said in a post on X.

"I have ordered all available federal assets on the Islands to help with response.

"And I urge all residents to continue to follow evacuation orders, listen to the instructions of first responders and officials, and stay alert."

It comes after three residents were left with critical burns after being forced to jump into the ocean, as wildfires affected the popular shopping and dining area known as Front Street.

Posting on X on Tuesday, the Coast Guard said 12 people had been rescued from the water off Lahaina.

The Coast Guard responded to areas where people had fled into the ocean to escape the fire and smoky conditions, the county said in a statement on Tuesday.

The governor of Hawaii, Josh Green, said on Wednesday that "loss of life is expected".

"We have suffered a terrible disaster in the form of a wildfire that has spread widely as a result of hurricane-force winds in the region and underlying drought conditions," he said.

"Maui and the Big Island both experienced significant fires. Much of Lahaina on Maui has been destroyed and hundreds of local families have been displaced."

At least 20 other patients were taken to Maui Memorial Medical Centre on Tuesday, Speedy Bailey, regional director for air-ambulance company Hawaii Life Flight, said.

Footage posted overnight showed flames affecting numerous buildings in the historic town centre, which dates back to the 1700s, and is listed on the National Register of Historic Places.

Some blocks of buildings were completely reduced to ash.

Kaniela Ing, who grew up in the area and co-founded the Native Hawaiian-focused organization Our Hawaii, described the destruction as "heartbreaking".

"If you start from one end of Front Street and walk to the other end, it's like a physical timeline of the history of the Hawaiian Kingdom," Mr Ing he told NBC - the US partner of Sky News.

"You can actually see the flow in the buildings stemming back 150 or more years. It's remarkable, and just the thought that that history may have been lost in this fire or any bit of that history is heartbreaking."

More than 2,100 people spent the night in four shelters on the island.

Kahului Airport, the main airport in Maui, was sheltering 2,000 passengers who had their flights cancelled or had only recently arrived at the island, the county said.

The National Weather Service said Hurricane Dora, which was passing to the south of the island chain, was partly to blame for gusts above 60mph (97kph).

The wind knocked out electricity, rattled homes and grounded firefighting helicopters. Flights resumed on Wednesday as the strong winds somewhat diminished.

The exact cause of the blaze has not yet been determined.

However, high winds, low humidity and dry vegetation, are likely to have contributed, according to Major General Kenneth Hara, adjutant general for Hawaii State Department of Defence.

Experts have also warned that climate change is increasing the likelihood of more extreme weather.

"Climate change in many parts of the world is increasing vegetation dryness, in large part because temperatures are hotter," said Erica Fleishman, director of the Oregon Climate Change Research Institute at Oregon State University.

Hawaii's Big Island have also been affected by fires, although no injuries or destroyed homes had been reported there.

Mayor Mitch Roth said one fire is "pretty much under control," another is 60% contained, and a third, near the hotel Mauna Kea Resorts, continued to flare up.

However, authorities have insisted that while West Maui is closed to tourists due to the wildfires, the state of Hawaii itself remains "open" and that rooms are available on the Big Island for those still hoping to travel.