A wildfire near Harrison Hot Springs, B.C., has spread and is of increasing concern to firefighters.

The B.C. Wildfire Service says the fire on the west side of Harrison Lake had grown to 100 hectares in size by Monday evening, and forced the evacuation of two nearby campgrounds.

Harrison Lake wildfire

The wildfire can be seen from across Harrison Lake, B.C. (CBC)

"It's in an area that has extreme fire behaviour and it's got quite a bit of fuel to bite into," said Donna MacPherson with the B.C. Wildfire Service.

"It's also an area that people do have a tendency to go to. It's a fairly heavily-used recreational area."

MacPherson said almost 30 additional crews were heading toward the area, putting a total of 71 personnel and four helicopters on the scene.

Campers at the Wood Lake and Twenty Mile Bay campgrounds were told to evacuate as a precaution. The B.C. Wildfire Service said the campgrounds aren't directly threatened, but the fire has affected the only road leading into and out of the sites.

RCMP officers have blocked the West Harrison Lake Forest Service Road until further notice.

Human-caused fire started Sunday

The fire started on Sunday afternoon and quickly grew, producing heavy smoke throughout the popular recreational area.

"This area is in high fire danger rating and this fire was human-caused and preventable," said MacPherson.

"We need people to be a lot more vigilant when they're out there and realize that anything they do could cause a spark."

The B.C. Wildfire Service said windy weather has created challenging conditions for crews. 

With files from the CBC's Kiran Dhillon