An aerial image shows destroyed homes and buildings burned to the ground in Lahaina on Thursday. AFP

Search and rescue teams with cadaver dogs were deploying meanwhile to look for victims of what Governor Josh Green said was "likely the largest natural disaster in Hawaii state history."

"What we've seen today has been catastrophic," Green said after touring Lahaina, a town of some 12,000 people which served as the capital of the Hawaiian kingdom in the early 19th century.

 An aerial image shows destroyed homes and buildings burned to the ground in Lahaina. AFP

The Maui County Government said firefighters were trying to extinguish flare-ups and contain wildfires in Lahaina and two other areas of the island on Friday.

It said additional firefighters from the Honolulu Fire Department had arrived on Maui along with search and rescue teams equipped with K-9 cadaver dogs. Brushfires fuelled by high winds from a nearby hurricane broke out on Tuesday and rapidly engulfed Lahaina, a favorite tourist destination for the millions of people who visit Maui each year.

Wildfire wreckage is seen in Lahaina, Hawaii. AP

The flames moved so quickly that many were caught off-guard, trapped in the streets or jumping into the ocean in a desperate bid to escape.

"There's nothing left, it's gone, it's a ghost town," said Sarai Cruz, 28, who fled Lahaina with her parents, sister and three children.

Brandon Wilson, a Canadian who had travelled to Hawaii with his wife to celebrate their 25th anniversary, said "it really looks like somebody came along and just bombed the whole town.

"It's completely devastated," said Wilson, who was at the airport with his wife trying to get a flight out. "It was really hard to see. You feel so bad for people. They lost their homes, their lives, their livelihoods."

The fires follow other extreme weather events in North America this summer, with record-breaking wildfires still burning across Canada and a major heat wave baking the US southwest.

Europe and parts of Asia have also endured soaring temperatures, with major fires and floods wreaking havoc.

'Completely destroyed'

Green, the governor, said he expected the death toll to exceed Hawaii's worst previous natural disaster, a large wave which left 61 people dead in 1960 on the Big Island. The death toll currently stands at 55 but "the number has been rising and we will continue to see loss of life," he said.

Images taken by an AFP photographer who flew over Lahaina showed it had been reduced to blackened, smoking ruins.

The burned skeletons of trees still stand, rising above the ashes of the buildings to which they once offered shelter.

Green said 80 per cent of the town was gone — "completely destroyed." Thousands have been left homeless and Green said a massive operation was swinging into action to find accommodation. "We are going to need to house thousands of people," he told a press conference.

President Joe Biden on Thursday declared the fires a "major disaster" and unblocked federal aid for relief efforts, with rebuilding expected to take years.

Pope Francis on Friday offered his prayers to the people of Hawaii and said he was "deeply saddened" by the tragedy.

Water rescues

US Coast Guard commander Aja Kirksey told CNN around 100 people were believed to have jumped into the water in a desperate effort to flee the fast-moving flames as they tore through Lahaina.

Kirksey said helicopter pilots struggled to see because of dense smoke, but that a Coast Guard vessel had been able to rescue more than 50 people from the water.

Thousands of people have been evacuated from Maui, with 1,400 waiting at the main airport in Kahului overnight, hoping to get out. Maui County has asked visitors to leave "as soon as possible," and organised buses to move evacuees from shelters to the airport. The island hosts around a third of all the visitors who holiday in the state, and their dollars are vital for the local economy.

Thomas Smith, a professor with the London School of Economics, said that while wildfires are not uncommon in Hawaii, the blazes this year "are burning a greater area than usual, and the fire behavior is extreme, with fast spread rates and large flames."

As global temperatures rise over time, heat waves are projected to become more frequent, with increased dryness due to changing rainfall patterns creating ideal conditions for brush or forest fires.