Thousands of passengers at one of the UK's busiest airports are experiencing flight disruption after drones were seen over the airfield.
Gatwick's runway remains closed after two of the devices were seen nearby.
About 10,000 passengers were affected as flights were unable to take off and incoming planes were redirected - with some landing in Paris and Amsterdam.
Chief operating officer Chris Woodroofe said staff were trying to find a drone reported as still being in the air.
The airport said 110,000 passengers were due to either take off or land at the airport on 760 flights on Thursday.
Those due to travel have been told to check the status of their flight, while Easyjet told its passengers not to go to Gatwick if their flights have been cancelled.
European air traffic management group Eurocontrol said the runway would remain closed until 11:00 GMT.
The shutdown started just after 21:00 on Wednesday when two drones were spotted being flown over the airfield.
The runway was briefly reopened at about 03:01, the airport said, but forced to close again about 45 minutes later amid "a further sighting of drones".
Police units and a helicopter were still hunting for the drone operator after another device was reported just before 07:00.
Mr Woodroofe told the BBC two drones had been seen flying "over the perimeter fence and into where the runway operates from", sparking "very significant disruption".
He said police had not wanted to shoot the devices down because of the risk from stray bullets.
It is illegal to fly a drone within 1km of an airport or airfield boundary.
Planes were diverted to other airports including London Heathrow, Luton and Manchester.
Aviation website airlive.net said some services were re-routed as far away as Cardiff, Paris and Amsterdam.
Crowds of passengers waited inside Gatwick's terminal for updates, while others reported being stuck on waiting planes for several hours.
Kasia Jaworska told the BBC she had been travelling from Glasgow to Gatwick with her boyfriend when her flight was diverted to Luton.
After spending about two hours on the plane, she said the couple were put on a bus to Gatwick, from where they had been due to fly to Istanbul.
Ms Jaworska said she thought it was "strange" that two drones had led to the closure of the airport.
"You would imagine there would be better security in place and emergency action for something like that," she added.
Christopher Lister, who had been returning from Kiev, posted a picture of people sleeping "on every seat and across the floors" on board his flight.
He said the photo was taken six hours after the plane - which was due to arrive at Gatwick - landed in Birmingham.
Luke McComiskie, whose flight ended up in Manchester, described chaotic scenes as people tried to find their way home after more than three hours stuck onboard.
The 20-year-old, from Aldershot, told the Press Association: "We got told there would be some arrangements with coaches for us when we get out the terminal.
"It was just chaos and they had only two coaches and taxis charging people £600 to get to Gatwick."
Eddie Boyes said he and his family had been at the airport for six hours and people were sleeping on the floor.
Drones and airports
The law says:
- It is illegal to fly a drone within 1km of an airport or airfield boundary
- Flying above 400ft (120m) - which increases the risk of a collision with a manned aircraft - is also illegal
- Endangering the safety of an aircraft is a criminal offence which can carry a prison sentence of five years
Gatwick Airport said airlines were "working to provide affected passengers with hotel accommodation" or provide alternative travel options.
A spokesman apologised for any inconvenience and said staff were working alongside Sussex Police to investigate the drone sightings.
British Airways said a "very small number of flights" had been diverted.
According to its website, the airport expects to welcome a "record-breaking" number of passengers over this year's Christmas period.
It predicts 2.9m people will pass through its gates during the festive getaway, with 73,000 of those due to depart this Sunday.
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