TENS of thousands of passengers face Christmas chaos after a mystery drone forced London's Gatwick Airport to close.

The holiday hub, Britain's second biggest, was due to handle 110,000 people on Thursday, one of its busiest days of the year.

Managers ordered a shutdown on Wednesday evening after a drone was spotted above the runway.

READ MORE: Gatwick Airport said its runway has now reopened but flights remain suspended after drones were spotted in the early hours.  

That move has had severe knock-on effects in Scotland, with at least 22 flights cancelled.

Glasgow Airport said four arrivals and five departures to London had been cancelled - and that it had offered an alternative landing to a cross-Atlantic WestJet flight from Toronto that was supposed to go to Gatwick.

Aberdeen has cancelled at least one departure. Inverness has dropped a total of four flights, two each way to Gatwick.

There are four more services scheduled between Glasgow and the London airport today and at least one from Aberdeen.

Services between Edinburgh Gatwick have also been affected. The airport said a total of eight services, split equally inbound and outbound, had been cancelled. One more is at risk.

There are regular shuttles between Scotland and Gatwick by both easyJet and British Airways. 

Airlines are understood to be trying to make alternative arrangements for passengers to go to and from other London airports. One railway company has offered free fares between Edinburgh and London for those who have missed air bookings.

READ MORE: Gatwick travel chaos: What are the rights of passengers? 

Speaking at 12:30pm a Gatwick spokesman said a drone had been seen "within the last hour" and was unable to say when the airport would re-open. Extra staff have been rushed to the airport.

A spokesman for Theresa May said flying drones over an airport was "irresponsible and completely unacceptable".

He added: "These drones have been flown illegally and the law couldn't be clearer that those found endangering aircraft could face up to five years in jail.

"We are in close contact with Gatwick Airport as they work with police to safely resolve the situation as quickly as possible."

Police said: "We believe this to be a deliberate act to disrupt the airport."

Offcers were looking for whoever was flying the drone, believed to be a heavy industrial machine. Sussex Police said they did not believe the incident was terrorism related by Sky News showed photographs of marksmen on the runway. Sources have said it is too dangerous to shoot down the drone.

HeraldScotland:

Passengers at Gatwick

Officers from Sussex and Surrey police were deployed onto the airfield and surrounding areas and were joined by a National Police Air Service helicopter to track down the drones and the operators.

Supt Justin Burtenshaw, a Gatwick Airport policing commander, said: “We believe this to be a deliberate act to disrupt the airport.

“However, there are absolutely no indications to suggest this is terror related.”

Chris Woodroofe, chief operating officer at Gatwick, told Sky news: "I would like to apologise to all the passengers who have been disrupted by this irresponsible act.

"Last night at nine o'clock a drone was spotted by two different members of my staff. As a result we had to close the runway for movements. Since then the drone has appeared and disappeared through until 3 o'clock in the morning we re-opened the airport feeling that it had gone.

"It came back again at 3.45am. So We closed the runway at 3.45 and it remains closed now. As I stand here there is a drone on my airfield as we speak."

HeraldScotland:

Grace Lyons arrived at the airport 29 hours ago and passed through immigration twice before being redirected to Stansted airport.

The 32-year-old, from Herne Hill, south London, said: “Its an absolute mess.

“I’m going home to Ireland and have very little time as it is, this has

essentially cut two days off my family time.

“We have no idea what's going and the airport staff, although very nice, have no idea what's going on either.

“We've come through immigration twice. It's very worrying that a few drones can shut down an airport for so long. It's very likely this will happen again.”

Patrick Campbell, 29, arrived at the airport at midnight, for a 6.20am take-off, to find the security shutters locked shut.

The executive chef was due to fly to Stockholm with Norwegian Airlines to spend Christmas with his Swedish girlfriend.

But after passing through security and spending £100 on duty free gifts, he

was ‘spat back out of customs’ and has not slept in almost 30 hours.

HeraldScotland:

Grounded aircraft at Gatwick

Mr Campbell, from Bristol, said: “Its so frustrating, it’s ridiculous. When I first heard about the drone, I thought it was just kids messing around and never expected it to lead to this.

“It’s unbelievable all the disruption it’s caused and the queues to rebook are crazy - they go back the entire length of the terminal.

“The roll shutter was locked when I got here at midnight so nobody could get through to security.

“Security officers lifted the shutters at 3am and congratulated me as the first person to be let through the gates - we were all laughing and joking at the time.

“I went through the whole security process and spent £100 on some expensive Talisker whiskey for my girlfriend’s dad as a present.”

When Mr Campbell arrived at the boarding gate, the screen said ‘boarding’ but there was nobody at the desk and the door was closed.

Passengers were left in limbo until 7.30am - an hour after Mr Campbell’s scheduled departure - when they were told by airline staff their flights were cancelled.

He said: “We were all instantly directed away from the waiting area, there must have been hundreds of passengers.

“Anyone with checked luggage had to collect it and queue to speak to one of two assistants at the desk to make alternative arrangements.

“I started queuing at 8am which feels like a lifetime ago and I am still stuck here and unable to fly.

“I’ve paid £60 for a week’s parking which I won’t get refunded, I can’t drive after not sleeping for 29 hours and most frustratingly I need to get to Stockholm."

HeraldScotland:

Empty runway at Gatwick

Passenger Laura Hudson Woodward was ‘one of the lucky ones’ to be transported to Southampton airport for her flight to Guernsey, which was scheduled to depart at 8.30am.

The 38-year-old communications officer is flying with her son to spend Christmas Day with her parents.

Ms Woodward, from Kent, said: “We’re now being taken by coach to fly out of Southampton.

“I’m so relieved to be honest, I guess I’m one of the lucky ones - it could have been so much worse.

“The airport staff have a lot to manage and seem to be doing their best to deal with the situation.”

Jelly Willmott has lost out on valuable time with relatives in Los Angeles

and said she has been ‘killing time’ at the airport shops since she arrived at the airport with her two daughters this morning.

She said: “We’ve been stood in this queue for hours so me and the girls are taking it in turns to wander around the airport to stretch our legs.

“I met people this morning who had a daytrip to Lapland booked and their whole Christmas trip has been cancelled, it’s awful.”

Airport staff confirmed they are prioritising passengers’ safety and suspended all 670 flights scheduled for today following reports of drones flyingover its airfield last night and this morning.

A spokesperson for Gatwick Airport said: “There is significant disruption

at Gatwick today and we are prioritising the welfare of those at the airport by deploying staff into our terminals to look after people as best we can.

“We are working hard with our airlines to get information to passengers but would advise anyone booked onto flights from Gatwick, or meeting arriving

passengers, not to travel to the airport without checking the status of the flight with their airline.

“We apologise for the continued inconvenience, but the safety of all passengers and staff is our first priority.”