Washington, Aug 25 (IANS): Authorities declared all-clear Monday at a US army base in Virginia following its lockdown due to an "active shooter incident".

"An all clear has been issued by the Fort Lee installation operations centre at 9.50 a.m." CNN quoted the army installation as saying in its Facebook page.

The law enforcement event is over, it said.

Earlier, the Fort Lee installation in Virginia was locked down after the incident was reported at Building 5020 of the Combined Arms Support Command headquarters.

Fort Lee is near Petersburg, Virginia, and 135 miles south of Washington.

Retd. Maj. Gen. James "Spider" Marks, a CNN military analyst, described the base as a "very active" one with soldiers "routinely coming and going to get various types of training".

According to Sparks, in an active shooter situation, everyone locks down in place to avoid becoming a target while letting authorities and military police respond.