London's Heathrow Airport says all flights have resumed after earlier disruption following a reported drone sighting.
Management at the airport said departures were stopped for a time as a precautionary measure while an investigation was carried out.
It apologised to passengers for any inconvenience as one of its two runways was closed.
The airport said it worked closely with British police "to prevent any threat to operational safety."
It is not known if a drone was actually discovered.
It followed days of flight disruption just before Christmas, after a drone was repeatedly flown near the runway of neighbouring Gatwick Airport.
We continue to work with the Met Police on reports of drones at Heathrow. We are working with Air Traffic Control and the Met Police, and have resumed departures out of Heathrow after a short suspension. We will continue to monitor this and apologise to anyone that was affected.
— Heathrow Airport (@HeathrowAirport) January 8, 2019
There was major disruption at Gatwick between December 19th and 21st due to the sightings, with hundreds of flights cancelled.
While the British army initially installed specialised anti-drone technology in a bid to combat any drones, it has since been removed.
Gatwick is said to be investing in dedicated anti-drone defences in a bid to avoid any similar disruption in the future.