Flights halted at Reagan National Airport due to security issue

The latest: An FAA notice announced the temporary ground stop was lifted Tuesday afternoon. Instead, flights would face a delay.

• FAA notices show a ground stop began at 11:18am ET as authorities responded to what the agency listed as a "security" issue.
• An FAA spokesperson told Axios in an emailed statement that runways reopened at 12:50pm ET.
• By 12:56pm ET, the FAA replaced the ground stop with a ground delay program, citing "Other/Security" as the reason.

Catch up quick: A United Airlines flight landed at the airport around 11:30am before temporarily waiting at an adjacent runway "in response to a security threat," the airport told Axios.

• All runways were then closed until passengers were safely evacuated and bused to the terminal, leading several other flights to be diverted to other airports.
• Reagan National's police are "conducting a thorough investigation with the assistance of multiple law enforcement partners," and passengers flying this afternoon should expect delays.

• The FAA told Axios that it is "aware of a reported security issue" and confirmed that authorities are investigating.

Go deeper: Reagan airport in D.C. has the country's busiest runway. Here's why - Axios Washington D.C.

Editor's note: This story has been updated with the latest developments and additional FAA and airport statements.