By Daniel Strauss - 04/17/13 04:58 PM EDT
The message directed staff and other personnel to avoid those areas until further notice. Capitol Police told staffers in the buildings to remain in their offices and ushered people out of hallways.
Another suspicious package was reported in Saginaw, Mich., at Sen. Carl Levin’s (D-Mich.) district office.
Later Wednesday afternoon Levin said that staffers were taken to the hospital as a precautionary measure.
"The staffer who discovered the letter is being kept overnight at a local hospital for precautionary reasons, but has no symptoms," Levin said in a statement. "We do not know yet if the letter has any connection to suspicious mail sent to other public officials. I want to repeat how grateful I am to local, state and federal authorities who reacted so quickly and professionally, and especially to my Saginaw staff for being so vigilant."
For more on the investigation, click here.