NEDERLAND — Investigators say a homemade exploding target started a small wildfire near Nederland on Sunday.

The U.S. Forest Service said Monday that rangers and the Boulder County Sheriff's Office are looking for the person or people responsible for igniting the target. Anyone with information is asked to call the Forest Service's Boulder district office.

The approximately 4 acre fire has been mostly contained and the chances of it spreading beyond its perimeter are considered small.

Exploding targets are used for shooting practice and explode when hit by a bullet. They are banned on the Arapahoe and Roosevelt National Forest, where the fire broke out.

They've sparked other larger fires, including the Springer Gulch Fire Lake George in 2012.