The air traffic control tower at Gatwick Airport is seen through fields in southern England, Britain, October 9, 2016.
Gatwick Airport has briefly suspended all flights after two unmanned aerial vehicles were spotted over the airfield. Flying a drone within 1km of an airport or airfield boundary was made illegal in Britain at the end of July.
In a statement, the airport said: "Following reports of two drones flying over the Gatwick Airport airfield at around 9pm, the airfield was closed from 21.03 on Wednesday 19th December to 03.01 on Thursday 20th December".
Gatwick announced that the runway had reopened at about 3am - but just 45 minutes later it was shut again.
Gatwick's statement did not provide an estimate for the resumption of flights.
Some passengers tweeted that they were stuck on planes at Gatwick while others said they were diverted to Heathrow and Manchester.
Gatwick officials said two drone were sighted near the runway.
"Our airlines are working to provide affected passengers with hotel accommodation or transport passengers landing at other airports to Gatwick by other means, and Gatwick staff are looking after passengers in our terminals".
British Airways (BA) told one customer who complained via Twitter, that Gatwick had "stopped all arrivals and departures due to a drone".
Some airline passengers reported heightened tensions on some diverted flights, resulting in police involvement.
He blasted the "irresponsible" act, telling BBC Radio 4's Today programme that 10,000 people had been affected by the closure, including 2,000 whose flights had been unable to take off.