Earlier in the day, Whitehall from Parliament Square to Horse Guards was shut down over a suspicious package that turned out not to be dangerous, Sputnik News reported.
The package was discovered at a check-in kiosk for El Al Israel Airlines. Police sealed off and evacuated the surrounding area and all flights from the airport were initially to be delayed.
The situation was quickly resolved, however, and Home Affairs correspondent for the BBC Daniel Sanford tweeted shortly after news of the suspicious package broke that it had been cleared from the terminal.
Officials later said that the terminal was open again, adding that the situation "is not a lockdown."