Flights into Gatwick Airport have been diverted after reports of a drone flying close to the runway.
EasyJet and British Airways confirmed they were affected by the disruption after the airport was forced to close a runway on Sunday evening.
A Gatwick Airport spokesman said: "Due to reports of a drone observation in the vicinity of the airfield, runway operations at Gatwick were suspended between 18:10 BST and 1819, and again from 1836 to 1841, resulting in a small number of go-arounds and diverts.
"Operations have resumed and the police continue to investigate."
Four EasyJet flights were diverted during the runway closure, a spokeswoman for the airline said.
"Once refuelled easyJet plans to continue three flights on to London Gatwick and is arranging coach transfers on to London Gatwick for passengers on flight EZY8832 from Bodrum that diverted to London Southend," she added.
"The safety and wellbeing of our passengers and crew is always easyJet's highest priority.
"While the circumstances are outside of our control, easyJet apologises for any inconvenience caused."
British Airways was also forced to divert one of its planes from Valencia to Bournemouth Airport, which is expected to take off again shortly, a spokesman said.
Among the passengers on the diverted flights was Holly Johnson, formerly the front man of British band Frankie Goes To Hollywood.
He wrote on Twitter: "A Drone on the flightpath into Gatwick : our @British_Airways flight diverted to Bournemouth. On the Tarmac waiting ... for an update"
It is not the first time a drone is suspected of infringing on airspace near landing strips.
Last month an airline pilot was forced to take evasive action after one came within 20 metres of his plane as he prepared to land in Edinburgh.
The Loganair flight had been descending at about 4,000ft at the time, and despite the safe landing police warned there could have been "far more serious consequences".