A hunter on the lookout for squirrels accidentally shot a bow hunter in the head in western Wisconsin.

According to the Trempealeau County sheriff’s department, the hunter saw movement by a tree and, thinking it was a squirrel, fired at it in the town of Gale.

He then realized it was a bow hunter sitting against a tree. The injured hunter was airlifted to a La Crosse hospital with serious injuries. The sheriff’s department didn’t immediately release the hunters’ names.

A message left at the sheriff’s department Sunday seeking an update on the injured hunter was not immediately returned.

The sheriff’s department classified the shooting as an accident. The Wisconsin Department of Resources is investigating.