Three flights have been diverted to Stansted Airport following reports of a possible drone sighting at Gatwick Airport.
The two easyJet flights - one from Barcelona and one from Amsterdam - both initially got sent to Stansted before taking off again to land at Gatwick. A British Airways flight from Heraklion was also diverted.
All three passenger planes eventually landed at Gatwick more than 90 minutes after their scheduled arrival time.
One person tweeted that he was landing in Gatwick when the pilot "assessed that we were going to have a little delay because of a drone". The passenger added that they landed after 15 minutes.
Another person tweeted that his easyJet flight to Gatwick had been "redirected to Stansted due to a drone sighting as we came into land". He said that the plane was refuelling and returning back to Gatwick.
A Stansted spokesman said he did not anticipate any further diversions.
A Gatwick spokesman said: "Gatwick investigated a report of an unconfirmed sighting of an object outside the airport's 5km exclusion zone today but - following a full assessment - the airport has remained fully operational throughout."
The latest disruption comes after Gatwick Airport was shutdown in the run up to Christmas last year with more than 140,000 passengers affected by the 33-hour shutdown of Britain's second busiest airport. Around 1000 flights were delayed or cancelled between December 19 and 21.
In the aftermath of the chaos, Gatwick and Heathrow purchased millions of pounds worth of military-grade anti-drone equipment in order to prevent a repeat of the incident.
Gatwick confirmed that it spent £5 million on new equipment, which is thought to include a mix of scanners, jammers and radars.
At the time, an airport spokesman said: "It means that Gatwick is now at a level of equipment equal to what the armed forces had supported us with."
Separately, dozens of firefighters were called to tackle a large blaze which broke out near Heathrow Airport in west London.
The fire, which led the firebrigade to tell residents to keep their windows and doors shut, caused disruption to trains to and from the airport.
At one point 10 fire engines and around 70 firefighters were dealing with the blaze at an old coal depot in Tavistock Road, West Drayton.
Fifteen people were evacuated from the scene shortly after the fire began at around 2pm. The cause of the blaze, which was accompanied by an explosion according to a witness, is not yet known. There were no reports of any injuries.