Justin Trudeau Photo: IC

Canada is sending the military to help evacuate and support communities hit by "catastrophic" flooding with the death toll expected to rise after record rainfall on the Pacific coast triggered a state of emergency Wednesday.

Officials said downpours in British Columbia this week trapped motorists in mudslides that left at least one dead and four missing, forced thousands of residents to flee their homes, and cut off Vancouver and its port.

Canadian Prime Minister Justin Trudeau, in Washington ahead of a meeting with his US and Mexican counterparts, said the heavy rains caused "historical and terrible flooding that has disrupted the lives and taken lives of people across BC."

"I can confirm there are hundreds of Canadian Armed Forces members currently headed to British Columbia to help with everything from supplies to evacuation to whatever is needed," he said.

British Columbia Premier John Horgan declared a state of emergency and imposed a travel ban, telling reporters "catastrophic" rains, winds and flooding "have devastated entire communities of our province."

"We expect to confirm even more fatalities in the coming days," he added.

This week's extreme weather comes after British Columbia suffered record-high summer temperatures that killed more than 500 people, as well as wildfires that destroyed a town.

"These events are increasing in regularity because of the effects of human-caused climate change," Horgan commented, just days after world leaders met in Glasgow for the COP26 climate conference.

By Tuesday afternoon the torrential rains had let up. An estimated 300 motorists trapped on highways by mudslides have been airlifted to safety and a few evacuation orders have been rescinded.

But Henry Braun, mayor of hard-hit Abbotsford east of Vancouver, told a briefing: "We're not out of this yet."

"If we have another weather event like we just went through, we are in deep doo doo."

Meanwhile, searches continue for more possible victims, after a woman's body was recovered from a mudslide near Lillooet, 250 kilometers northeast of Vancouver.

Motorist Kathie Rennie told public broadcaster CBC she witnessed "the whole side of the mountain coming down and taking out these cars... everything just being swept away. Just complete panic."

AFP