Dozens of firefighters were on the scene Saturday of a fire burning in dry grass and black spruce about five miles southeast of Fort Yukon, according to the Bureau of Land Management's Alaska Fire Service.

The fire, which was reported by a local resident Thursday and is believed to have been caused by humans, had burned over about 400 acres. The agency said smoke jumpers were sent to the scene and the fire was battled with retardant dropped from an air tanker and buckets of water from a helicopter.

A total of 71 firefighters were working the blaze early Saturday, the agency reported.

Firefighters planned to continue mop-up operations Saturday and possibly release some people to work on other fires.