"All Clear." The lock down on base has been lifted — Joint Base Andrews (@JBA_NAFW) June 30, 2016

The base was scheduled to conduct an active shooter exercise, however, reports of a real-world active shooter situation were reported. — Joint Base Andrews (@JBA_NAFW) June 30, 2016

JBA is currently on lockdown due to a report of an active shooter. All personnel are directed to shelter in place. More info as it comes. — Joint Base Andrews (@JBA_NAFW) June 30, 2016

The incident is ongoing at the Malcolm Grow Medical Facility. First responders are on-scene now. All personnel continue to shelter in place — Joint Base Andrews (@JBA_NAFW) June 30, 2016

PRINCE GEORGE'S COUNTY, MD -- A law enforcement official says no active shooter was found at a military post outside Washington.The law enforcement official was not authorized to discuss the matter by name and spoke on condition of anonymity.Joint Base Andrews had been placed on lockdown Thursday morning after an active shooter was reported. The base is home to Air Force One and is about 20 miles from Washington.An active shooter exercise had also been planned at the base, but officials said the situation became "real world."The situation unfolded at a medical facility on the post. Joint Base Andrews issued a tweet telling all personnel at the base in Washington's Maryland suburbs to shelter in place.We're following this story on Eyewitness News. Watch for updates on air, online and on our mobile news app.