Suspected drone activity in the vicinity of Gatwick led to a dozen aircraft having to be diverted to other airports.
The airport shut its single runway for almost an hour causing diversions for 12 inbound flights on Sunday afternoon.
British Airways, easyJet and Tui flights were among those diverted to Luton, Southend, Stansted and Bristol.
A Gatwick spokesperson said yesterday: “Operations at London Gatwick were suspended temporarily at 1.44pm, while investigations into the sighting of a suspected drone close to the airfield took place.
“These investigations have now completed and the airfield reopened at 2.35pm.
“Twelve inbound aircraft were diverted to other airports during the investigation, however we expect many of these to return to London Gatwick today.”
They added that passenger safety was the airport’s “absolute priority”.
Gatwick also took to Twitter with a reminder about rules restricting the use of drones within 5km of any UK airport and above 400ft.
It said: “When you fly a drone in the UK it is your responsibility to be aware of the rules that are in place to keep everyone safe. It is a criminal act to break the no-fly zone. You could put lives at risk and go to prison for up to five years.”
Last week it emerged that an easyJet aircraft had missed a drone by 16ft, about 5,000ft over the Sussex countryside.
The Airbus A320 had just taken off from Gatwick heading to Basel in Switzerland.
A report by the UK Airprox Board, the official body for assessing near misses, found that pilots initially thought the object was a bird before concluding it was a drone.
The pilots told air traffic controllers who put out a warning to other aircraft leaving Gatwick.
Flights in an out of the UK’s second largest airport were disrupted over three days in December 2018 due to what was through to be a drone, causing more than 1,000 flights to be cancelled affecting 140,000 passengers.