US Joint Base Andrews is on lockdown due to active shooter report

U.S. Navy photo by Photographer's Mate 2nd Class Daniel J. McLain via Wikipedia

US Joint Base Andrews near Washington DC was placed on lockdown on Thursday due to a report of an active shooter and personnel were told to shelter in place, base officials said on Twitter.

Joint Base Andrews is the military facility where the U.S. presidential aircraft, Air Force One, is based.

"The incident is ongoing at the Malcolm Grow Medical Facility. First responders are on-scene now," base officials said on Twitter.

An active shooter drill had been scheduled on the base for Thursday, but an 'real-world' active shooter situation was then reported around 9 a.m., base officials tweeted.

"Due to the serious nature of this report, the base is reacting to ensure the safety of all personnel," the officials said.

Homeland Security Secretary Jeh Johnson confirmed there is an "unfolding situation" at the base, but provided no further details, the Associated Press reported.

The U.S. military has been on high alert for possible attacks at U.S. locations after incidents such as the July 2015 shooting rampage that killed five service members at two military offices in Chattanooga, Tennessee, and the 2009 shooting at a U.S. Army base in Fort Hood, Texas, in which a gunman killed 13 people.

Andrews base in Maryland is the primary military air installation in the Washington, D.C., area, and is located about 15 miles from the White House.

Malcolm Grow is a full-service military hospital which according to its website is affiliated with the Uniformed Services University of Health Sciences and serves as a training facility for 48 medical residents and 31 health professionals.