DAYTON, Ohio - The Associated Press reports there was "no real world active shooter incident" at an Ohio Air Force base Thursday. The base Tweeted that someone mistook a training drill for a real active shooter.

A 911 caller believed there was a real threat, and security forces responded, according to the base. During the sweep of the hospital, a first responder fired a gun to open a door that was locked.

Wright-Patterson Air Force Base first stated via Twitter that they were responding to "a reported incident" at about 12:40 p.m. EDT Thursday. The incident was centered at the Air Force base’s hospital, near Dayton, Ohio.

The base’s public affairs office said the base was on lockdown and that personnel were told to shelter in place.

The Bureau of Alcohol, Tobacco, Firearms and Explosives, Ohio State Highway Patrol and local police were some of the agencies called to the base.

Earlier Tweets:

The Ohio State Highway Patrol and local police were sent personnel to the base.