Update: 12:20 pm: ” MPD reports the police activity has cleared on 12th Street between E and F Streets NW. The associated road closures are now open.”

From AlertDC:

“MPD reports 12th Street NW between E and F Streets NW is closed due to police activity. Please avoid the area.”

Readers report:

“firetrucks blocking off 12 & F NW. Hazmat suits and firemen going into a manhole??”

“This is my office building, we’ve been told it’s not a test and we aren’t allowed to leave/go into the stairwells. Hazmat everywhere.”

“an ever-growing presence of police/fire/EMT at 12th & F NW. Police have now extended perimeter past Harry’s to the intersection at 11th & F.”