UPDATE: The FBI has confirmed that reports of a shooter was just a drill. An all clear has been issued.

Joint Base Andrews, a naval air facility in Washington’s Maryland suburbs, is on lockdown after a report of active shooter.

Fox 2 reports that the situation began around 9a.m. when reports of an active shooter at the Malcolm Grow medical facility came in. 

A message posted to Facebook Thursday morning instructs all personnel at the base to shelter in place.

First responders are on the scene.

The post explains that the active shooter incident did occur at the same time that the base was scheduled to conduct an active shooter exercise.

Joint Base Andrews Public Affairs told Fox 2,

“We are reacting to a report of a real world active shooter. The call occurred during an exercise. Because the report came in as a real active shooter we have to respond accordingly. We are treating as if it is and no further information at this time.”