(Reuters) - An Air Force base in Ohio declared the area safe on Thursday after an exercise involving an active shooter scenario spurred a call to public emergency services and a response from security forces.

The hospital at Wright-Patterson Air Force Base had a scheduled training exercise that included an “active shooter scenario,” but an unknown individual believed the incident was real, the base said in a statement.

Personnel at the base near Dayton, Ohio, were initially told to shelter in place while the incident was investigated, and federal and local security officials responded to the scene.

“In an attempt to breech a door that was locked, a security forces member discharged his firearm to open the door and continue the sweep of the facility,” the base said in a statement.

Officials have declared the scene safe, although they are advising personnel to avoid the base hospital.