Washington — The Pentagon went into lockdown for roughly an hour Tuesday after a “shooting event” that occurred near the building’s Metro transit center, police said.

The Pentagon Force Protection Agency asked members of the public just after 11 a.m. to avoid the area, and the Arlington County Fire Department said on Twitter its units were “responding to a reported active violence incident” near the Pentagon’s Metro stop. Arlington County first responders encountered “multiple patients,” the fire department said.

Warnings sounded on intercoms throughout the facility telling all those inside to remain indoors “due to police activity outside.” 

About an hour after the Pentagon Force Protection Agency announced the lockdown, citing “an incident at the Pentagon Transit Center,” the agency said the “scene of the incident is secure” but remains an active crime scene. 

“We request that everyone stay away from the Metro rail entrance and bus platform area,” it said on Twitter.

The Pentagon Force Protection Agency announced just before 12:15 p.m. that the lock down was lifted and the facility reopened.

A bus terminal and Metro stop are located outside the Pentagon. The Washington Metropolitan Area Transit Authority said trains and busses were bypassing their stops at the transit center due to the investigation.