Firefighters continued Saturday to work toward tamping down a wildfire in northern Minnesota, wary of a Sunday forecast for windy, dry weather that could complicate the job.

On Friday, about 80 firefighters supported by aircraft succeeded in containing about 10 percent of the blaze, which began Thursday when a prescribed burn jumped its borders in the Boundary Waters Canoe Area Wilderness 10 miles west of Ely.

As of late Friday, the fire covered about 440 acres, down from 1,000 acres earlier in the day, the U.S. Forest Service reported. Crews attacked the fire on its north, east, and west sides, and aircraft dropped fire retardant along the east side of the fire and water on the west side.

Strong winds were predicted for Sunday, which could potentially increase the fire's size and speed. Crews prioritized the east side of the fire for Saturday's fire-suppression efforts, the Forest Service said. The earliest chance of rain over the fire area is Monday.

The blaze escaped containment on Thursday afternoon and spread north because of higher-than-expected winds and low humidity. Smoke has been visible from miles away.

There is no immediate threat to the towns of Ely, Winton, Tower or Soudan, the Forest Service says, and no structures are threatened, although local fire departments have been closely watching conditions around a few remote cabins. The Forest Service has closed the Crab Lake entry point to the BWCA, and several nearby portages and campsites.

The fire began as a prescribed burn of 78 acres near Foss Lake to reduce dead trees and brush and to encourage jack pine, a species that requires fire for regeneration. Dry, warm conditions are perfect for prescribed burns, but also increase the risk that a sudden change in weather can start a wildfire.