Firefighters battling the Mount McLean blaze one kilometre west of Lillooet, B.C., conducted a successful burn-off operation Monday night, effectively fighting fire with fire.

Ignition specialists used a helicopter-mounted torch to char the fuel situated between the eastern flank of the fire and the west side of town.

"We want to remove the fuel from the path of the fire so it has nothing left to burn," fire information office Garry Horley said Tuesday.

Burn-off missions are extremely dangerous, Horley said, but not uncommon, and fire behaviour specialists are always on hand to monitor the operations.

"We make sure all our stars are aligned before we put any matches to the ground," he said.

The Mount McLean fire currently covers 3,300 hectares of mountainside, and officials hope the burn-off zones may prevent the fire from creeping closer to residential homes.

In Pictures: Lillooet, B.C., wildfire

Seventy-five per cent of the burn-off area was completed Monday night, and officials hope to complete the remaining 25 per cent on Tuesday.

On Tuesday, crews began aggressively attacking spot fires while 16 helicopters and 19 pieces of heavy machinery worked on the east flank of the blaze, preparing for further burn-off missions.

Officials say the cooler weather forecasted today may help their progress, and the Chilliwack Fire Department dispatched two support crews to Lillooet Tuesday morning.

More than 2,000 residents were forced to abandon their homes on Sunday night after the rapid spread of the blaze brought the fire's frontlines dangerously close to town.

"I couldn't believe how fast it came down the mountain," T'it'q'et resident Ginger Alec said. "Faster than a rolling rock even."

The entire Lillooet District and the T'it'q'et and Bridge River reserves have all been evacuated - though dozens of residents are believed to have remained in their homes.

"It's always the case," Horley said.

"We hate to see that because we can't risk our crews to try and go in and save them when everything hits the fan."

So far, no structures have been destroyed in the wildfire, which is believed to have been sparked by lightning.

For information on the Mount McLean fire and other major fires burning in the province, residents can call a new information line at 1-888-350-6070.