UPDATE: 12:35PM - According to the Associated Press, reports of an active shooter at a military post outside Washington stemmed from someone who made a distress call after seeing security forces doing a routine inspection.
The confusion was heightened by a planned active shooter drill at Joint Base Andrews that had not yet begun and was planned for later in the morning. The base said in a Facebook post Thursday that there was no shooter and no threat to the base or workers there, the AP said.
The base had been placed on lockdown after an active shooter was reported. The base is home to Air Force One and is about 20 miles from Washington.