In a statement, a Heathrow Airport spokesperson said the drone was first sighted in the airport's vicinity at approximately 5:05 p.m. local time (12:05 p.m. ET) and that the airport was "working closely with the Met Police to prevent any threat to operational safety."
Departures were stopped as a "precautionary measure" during the investigation, the spokesperson said.
Some flight departures had resumed by 6:20 p.m., according to the aviation tracking website Flight 24.
