Flights were briefly suspended at Gatwick Airport on Friday evening after an unconfirmed sighting of a drone caused the transport hub's runways to be closed off.
London's Gatwick Airport said late on Friday afternoon that it had closed its runways again after new, unconfirmed reports of a drone near the transport hub.
But flights were only paused briefly while authorities investigated the sighting. The airfield was quickly re-opened.
It comes after chaos ensued on Wednesday night and throughout Thursday when the devices were spotted near runway.
The airport, south of London, reopened earlier on Friday and had started to introduce a limited number of flights.
The first flight of the morning was en route to Lapland — passengers aboard Lapland-bound flights tweeted their excitement after finally arriving.
British Airways said earlier on Friday that it had received confirmation from Gatwick that the airport was back open and "the majority of flights (were) operating as scheduled."
Easyjet said its services would resume but departures and landings would be restricted at first.
The airport advised passengers to check the status of their flight with their airline before travelling to the airport as departures and arrivals "will be subject to delays and cancellations."
Chris Woodroofe, the airport's chief operating officer, said the operator had not yet been found, but extra security measures in place ensured the airport could reopen.
Speaking of those extra safety measures, Transport Minister Chris Grayling told the BBC "military capabilities" had been deployed.
"What's happening on the ground is a mix of measures taken to give confidence that aircraft can be safe... Some of those are military capabilities," Grayling said.
"The reality is that this technology is only just emerging... there certainly isn't a straightforward commercial, off-the-shelf solution that automatically solves all problems."
Thousands of passengers remain stranded at the airport as police continue their search for the operator of the drones.
The British military announced they had deployed specialist equipment to tackle the presence of drones at the airport — the UK's second biggest.
Flight suspensions hit 10,000 passengers on Wednesday evening and a further 110,000 were due to take-off or land at the airport on Thursday.
Gatwick initially announced that its runway was closed for six hours from 21h GMT on Wednesday after two drones were spotted.
It re-opened for a mere 44 minutes before being shut down again after a further sighting of the devices.
"Unfortunately, this has led to a number of flights being diverted to other airports while aircraft have also been unable to depart from Gatwick," the airport said in the statement. "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."
More than 20 police units from two forces were searching for those responsible.
Sussex Police said it believed the incidents over the airfield were deliberate but said there are "absolutely no indications to suggest this is terror-related".
"Each time we believe we get close to the operator, the drone disappears; when we look to reopen the airfield, the drone reappears," said the force's Superintendent Justin Burtenshaw.
"Public safety is paramount and we will take all available actions to disrupt this deliberate act," the force added.
Chris Woodroofe, Gatwick's chief operating officer, told BBC radio that it would be dangerous to shoot at the drone due to the danger of stray bullets.
British Prime Minister Theresa May said that the drone activity in Gatwick was "illegal" and expressed sympathy for affected passengers.
Thousands of stranded passengers
Thousands of passengers were affected by the delays at Gatwick Airport and many were forced to wait aboard their aircraft for long periods of time.
Some airline passengers reported heightened tensions on some diverted flights, resulting in police involvement.
One passenger flying from Kiev, Ukraine, was diverted to Birmingham, and said passengers were forced to wait for hours on the plane after landing with "no food or updates."
And it wasn't just passengers who were stranded. Grounded pilots also shared their frustrations in posts to social media.
However, not all stories were negative. Some social media users affected by the airport closure shared posts offering lifts to stranded passengers.
Luton Airport worker Adam Webster, who said he was forced to work an extra five hours until 4 am due to diverted flights, offered lifts home to affected peoples living nearby.
"If there is anybody at Luton airport that has been diverted from Gatwick airport and needs a lift home, let me know," he wrote on Twitter. "Happy to help, I can't travel too far but anything to restore people's faith in humanity."
The UK's Department for Transport said the drone operator could face up to five years in jail, for Thursday's incident.
"These drones have been flown illegally and the operators, who have acted incredibly irresponsibly, could face up to five years in jail," the statement said.
"We are in close contact with Gatwick Airport as they work with police to safely resolve the situation as quickly as possible."