London's Heathrow airport suspended all departures on Tuesday due to reported drone sightings.
It came just weeks after a similar debacle left thousands of travelers stranded at Gatwick airport.
Departures from Britain's busiest airport were grounded for about an hour before being given the all clear.
Inbound flights were not affected.
Heathrow officials apologized for the delays, adding they are working with local police to investigate the incident.
