American flag. A north Alabama military post said in a tweet it was on lockdown Tuesday amid reports of possible active shooter. File picture: David Goldman/AP

Huntsville — A north Alabama military post said in a tweet it was on lockdown Tuesday amid reports of possible active shooter, telling workers to "run hide fight."

Redstone Arsenal received reports of a person possibly armed with a weapon at a building on the base, spokesperson Christopher Colster told WAFF-TV in a live broadcast.

Colster said there were no confirmed casualities and that officials hoped workers could return to normal activities within a couple of hours.

A safety drill was planned for Wednesday, but Colster said the report of a shooter was not part of any exercise.

Television stations in the area are quoting Huntsville Hospital officials as saying they've heard of no incoming patients

More than 30,000 government employees, civilians and contractors work daily at Redstone, which adjoins the city of Huntsville. It is home to Army missile defense programs and other military offices.

Nasa's Marshall Space Flight Center, which oversees rocket propulsion operations, also is located at Redstone.

Associated Press