US military Joint Base Andrews, just outside of Washington, DC, has been put on lockdown due to an active shooter reportedly barricaded inside the medical center. A "shelter in place" order is in effect.

Known as "America's airfield," Andrews is the home base of Air Force One, the airplane used by US presidents. It is located in Maryland, four miles southeast of Washington, DC.

The incident is apparently unfolding at the Malcolm Grow Medical Facility, the base authorities confirmed.

The shooter is barricaded on the third floor of the medical center, according to a reporter for the military newspaper Stars and Stripes.

Another report also said the situation was unfolding at the medical center, citing the Air Force.

There appeared to be some confusion whether the situation was real or part of an exercise scheduled for today. Base officials are saying the call came during an exercise, but the report is real.

“We are reacting to a report of a real world active shooter,” a spokesperson for the base told WTTG. “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.”

(RT)