A man is being treated for non-life-threatening injuries after he opened a backpack and had a reaction to what was inside.
It is unclear at this time if the man was an official or a bystander.
Police were called to the 400 block of 19th Street in Northwest D.C. for a suspicious package near the U.S. Office of Personnel Management and U.S. Department of Interior Museum.
Officials said all tests for hazardous material were negative.
They are clearing the scene to reopen C Street and Virginia Avenue Northwest.