On Friday, Reuters reported that the U.S. Capitol was on lockdown, according to police. The Associated Press reported that police are barring people from entering the building and that the "Senate sergeant at arms issued a lockdown alert." Reuters tweeted, "U.S. Capitol police looking for female who is possibly armed and possibly in basement of U.S. House office building," citing a Senate aide.
Update: The U.S. Capitol building is no longer on lockdown. At 9:43 a.m. on Friday, the Associated Press tweeted that a loudspeaker announcement on the ground stated that the lockdown was over.
The Associated Press also noted that Capitol police said they are "searching for an individual but offered no details." Business Insider's Oliver Darcy tweeted a screenshot of the alert message sent to Capitol Hill staff. The instructions included, "Close, lock, and stay away from external doors and windows," and "take annunciators, emergency kits, and escape hoods; move to your office's assigned shelter in place location or the innermost part of the office away from external doors or windows until UCSP has cleared the incident." Voting was scheduled to begin at 9:15 a.m. this morning, but had been postponed, according to the House press gallery.