People in the Dirksen Senate Office Building are being asked to stay clear of the area of room 221 (Sen. Wyden’s office) because a suspicious substance in an envelop is being investigated:

Police are investigating a "substance" in Sen. Wyden's office. Press being kept away.

A photo posted by Ginger Gibson (@gingergibson) on

The “all clear” has been given:

Editor’s note: This post has been updated with additional tweets.