Police are shutting down 12th Street S. between Army Navy Drive and S. Eads Street, near the Lenox Club and the Point at Pentagon City apartments.
Initial reports suggest that there is a man on one of the apartment balconies who is being uncooperative with police.
The incident started as a medical dispatch for a hand injury, possibly from the man punching a window or a glass door.
Police are currently trying to establish contact with the man, who is reported to have a history of mental health issues. Firefighters and medics are staging at the scene.