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A U.S. Army installation is in lockdown Tuesday following reports of a possible active shooter.

The Redstone Arsenal in Alabama issued an alert on Twitter of a “possible active shooter on the Arsenal.”

Redstone Arsenal urged those to “run, hide, fight” in instructions on how to deal with an active shooter situation.

redstone - BREAKING: Alabama Army installation locked down over 'possible active shooter'

There were reports of a shooter at Building 5301, the aviation and missile command building, at the post’s Sparkman Center, Army Spokeswoman Kim Hanson said, according to CNN.

Redstone Arsenal Spokesperson Christopher Colster told AL.com that there are no confirmed casualties at this point.

madison - BREAKING: Alabama Army installation locked down over 'possible active shooter'

An email was sent out to employees at the Redstone Arsenal at 10:31 a.m. that this reported active shooter was “a real world event, which is not part of the exercise,” AL.com reported.

The facility was reportedly conducting active shooter drills this week.

Alabama Gov. Kay Ivey said she is being updated on the situation.

Ivey - BREAKING: Alabama Army installation locked down over 'possible active shooter'

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