“Most homes” and structures have been destroyed and multiple residents are unaccounted for in the town that recorded the highest temperature during Canada’s devastating heatwave.

1,000 residents from Lytton and the surrounding area were evacuated on Wednesday night as flames engulfed the town in the mountains of British Columbia that reached 49.6C this week.

Photographs from the ground and the air show total devastation, with large family houses reduced to piles of ash and trees turned to charred trunks.

The fire overwhelmed Lytton, nestled in a steep-sided valley 95 miles northeast of Vancouver, in hours.

Aerial photographs reveal the devastation on the ground

Credit: Darryl Dyck/The Canadian Press via AP

"It’s dire. The whole town is on fire," Jan Polderman, the mayor, told CBC News on Wednesday. "It took, like, a whole 15 minutes from the first sign of smoke to, all of a sudden, there being fire everywhere."

He ordered the evacuation at 6pm that evening.

By Thursday morning the devastation was clear.

“Our poor little town of Lytton is gone,” one resident, Edith Loring Kuhanga, wrote on Facebook. “This is so devastating – we are all in shock! Our community members have lost everything.”

Mike Farnworth, British Columbia’s public safety minister and solicitor general, told a press conference that “most homes” and structures in the village had been destroyed including an ambulance station and an outpost of the Royal Canadian Mounted Police.

The fire rapidly took over the town

Credit: 2 RIVERS REMIX SOCIETY / VIMEO.2RMX.CA

Officials are now struggling to locate and account for everyone who was scattered during the evacuation.

"We are receiving calls from people looking for family and loved ones as well, and it’s really hard because of power outages and cellphone towers being down, but we’re working on that," Scott Hildebrand, a chief administrative officer with the Thompson-Nicola Regional District, told CBC News.

The cause of the fire was still being investigated, said John Horgan, the premier of British Columbia, but he vowed to rebuild.

“When the smoke in Lytton clears, of course, the province will be there to rebuild,” Mr Horgan said.

“I made that commitment to the mayor today and I make that commitment to those who are in emergency centres around the region.”

He said he had spoken to Prime Minister Justin Trudeau, who had offered federal assistance.

How a heat dome is formed

The extreme temperatures have been caused by a "heat dome" of high pressure that has trapped hot dense air at ground level. In Lytton, thermometers peaked at 49.6 Celsius (121 Fahrenheit)

With the “heat dome” now moving east into Canada’s prairie provinces, there are fears that sudden deaths and wildfires will follow it.