OTTAWA: Relentless rain battered Canada's Pacific coast on Monday, forcing evacuations and sending mudslides, rocks and debris across major highways that left motorists trapped east of Vancouver.

"Heavy rains and subsequent mudslides/flooding have impacted various highways in the BC interior," British Columbia's transportation ministry said on Twitter.

Rescuers were deployed to free people trapped for hours in 80-100 cars and trucks between two mudslides near the town of Agassiz, the province's safety minister, Mike Farnworth, told a news conference.

"We are looking at the possibility of air rescues, if needed," he said, adding that "high winds may challenge these efforts."

Farnworth said there had been "multiple rain-induced incidents" in the southwest and central regions of the province, adding: "The situation is dynamic."

In the city of Abbotsford, outside Vancouver, authorities ordered more than 100 homes evacuated in several neighborhoods threatened by flooding and mudslides.

The town of Merritt, 190 kilometres (120 miles) east of the coastal city, also urged some 2,000 residents to leave after their wastewater treatment plant was compromised, according to Farnworth.

"The entire community (of 7,000 people) may have to be evacuated," he said.

Emergency centers were set up in both communities for displaced residents.

Environment Canada said in a statement up to 250 millimetres (almost 10 inches) of rain was expected by the afternoon in and around Vancouver, which was also hit last week by a rare tornado.

"A significant atmospheric river event continues to (bring) copious amounts of rain to the BC south coast today," it said.

"Heavy rain will continue this morning and ease this afternoon as the system moves inland."

Environment Canada meteorologist Armel Castellan said strong winds gusting up to 90 kilometers per hour (55 miles per hour) could cause widespread power outages.

The extreme weather comes after British Columbia suffered record-high temperatures over the summer that killed more than 500 people, as well as wildfires that destroyed a town.