Flights have resumed again this evening at Gatwick Airport in London.
There was a temporary suspension this evening follows an unconfirmed report of a drone sighting over the airfield.
In a statement after an investigation, airport authorities said flight activity was resuming as they were confident anti-drone military measures in place at the airport have offered them the 'necessary reassurance'.
Flights have now resumed. Airfield movements were suspended while we investigated this as safety remains our main priority. The military measures we have in place at the airport have provided us with reassurance necessary to re-open our airfield.
— Gatwick Airport LGW (@Gatwick_Airport) December 21, 2018
Earlier, the airport reopened after services were suspended all day on Thursday amid drone sightings.
The disruption began at around 9.00pm on Wednesday when the airport reported that flights had been suspended and there were "reports of two drones flying in and around the airfield".
It said late Thursday it could not be re-opened following further appearances of the devices.
Police and airport authorities believe they were being flown in deliberate act to disrupt the airport.
The unusually large drones had been spotted near the airfield more than 50 times over the 24-hour period, police said on Thursday night.
Detective Chief Superintendent Jason Tingley said officers believe the device is "larger than a domestic drone."
"Our working assumption is it's larger than what someone might buy online, we think it may have been adapted and developed."
He said firearms officers were now considering shooting the device down, despite authorities earlier saying that would be dangerous due to the danger of stray bullets.
"We have to take into consideration other people that may be in range and the impact of firing at a drone," Detective Tingley added.
Passengers stranded queue for information at London's Gatwick Airport | Image: Victoria Jones/PA Wire/PA Images
Gatwick's chief operating officer Chris Woodroffe said it is a "terrible situation" for the 120,000 people who have had their travel plans disrupted.
"The issue from my perspective is that this is a criminal act, purposefully undertaken in order to cause this disruption, and I very much hope we bring the perpetrator to justice."
Gatwick, which is around 50km south of London, is the eighth-busiest airport in Europe and sits behind Mumbai as the world's busiest single runway air hub.
Picture by: Kirsty Wigglesworth/AP/Press Association Images
Around 10,000 passengers were affected on Wednesday night, and a further 110,000 who had been due to either take off or land at the airport on 760 flights on Thursday.
Aer Lingus earlier said they were planning to operate all flights from Gatwick today.
We intend to operate all flights to/from Gatwick today, subject to airspace remaining open. However, there are delays on all Gatwick flights so please check flight status before travelling. We're working hard to ensure everyone gets to their planned destination for Christmas ??
— Aer Lingus (@AerLingus) December 21, 2018
Ryanair, meanwhile, said its flights scheduled to operate to and from London Gatwick on Friday would instead operate to and from London Stansted.
It adds that all affected customers have been notified.
Travel update: Ryanair flights scheduled to operate to/from London Gatwick tomorrow (21 Dec) will instead operate to/from London Stansted. All affected customers have been notified by our Customer Care team https://t.co/96cDH8V0oJ
— Ryanair (@Ryanair) December 20, 2018
Additional reporting: IRN, Stephen McNeice
