LONDON -- The Latest on London airport closure because of drones (all times local):
The chief executive of London's Gatwick Airport says the drone intrusion that shut the airport was "highly targeted" and designed to cause "maximum disruption" just before Christmas.
Stewart Wingate said in a statement issued on Thursday that it was "regrettably" not clear when the airport would be able to resume flights safely because the drones still were a threat.
Wingate says the airport closed down after two drones were reported to be flying around Gatwick's airfield Wednesday evening. He says drones pose a big strategic challenge for the aviation industry and steps must be taken to prevent future airport shutdowns.
Wingate also apologized to passengers. He said: "We are all working flat out to minimize inconvenience and have additional staff in both terminals assisting passengers who are waiting." he said.
British officials plan to lift some night-flight restrictions to ease travel backups from the drone-induced closure of London's Gatwick Airport.
Transport Secretary Chris Grayling told Sky News on Thursday the move is needed because of the problems at Gatwick.
Grayling said: "One of the things we're going to be doing is temporarily lifting the night-flight restrictions at other airports so more planes can get into and out of the country."
He did not provide details about where night flights would be allowed and apologized in advance to residents who might be affected by noise from planes that typically are barred from flying late night and early morning hours.
More than 100,000 people have been affected by the Gatwick shutdown.
British troops may be sent in to help hunt drones that have shut down Gatwick Airport.
Police have been searching the area around the airport for operators of drones spotted over the airport on Wednesday evening.
Britain's second-busiest airport remains shut more than 18 hours later, and more than 100,000 travelers have been disrupted.
European air-navigation agency Eurocontrol says the airport is not due to reopen until at least 8 p.m. (2000GMT, 3 p.m. EST) on Thursday.
The Ministry of Defense says "there are ongoing discussions with the police about any military capability that could be provided to assist with their operation."
A body that represents British air traffic controllers says regulators have repeatedly ignored its calls for tougher measures against drones near aircraft.
The Guild of Air Traffic Control Officers says it has urged geofencing — the use of software to stop drones flying into restricted airspace — and other counter-drone measures, but its calls "have been repeatedly dismissed by regulatory bodies."
The guild says the disruption at Gatwick Airport on Thursday is unprecedented, but "such an event will continue to be a threat until appropriate measures are taken."
Hundreds of flights have been canceled and more than 100,000 travelers disrupted at the U.K.'s second-busiest airport since drones were spotted over the airfield on Wednesday evening.
Police are scouring the area for the drone operators.
British Prime Minister Theresa May says the government is considering "further police powers" to deal with the threat from drones to aircraft.
Tens of thousands of passengers have been disrupted in a shutdown of London's Gatwick Airport because drones were spotted over the airfield. Police are searching for the drone operators.
May says using a drone to endanger aircraft is a crime punishable by up to five years in prison. She says "we are consulting on further aspects" of legal enforcement, "including further police powers."
May told reporters that "I feel for all those passengers whose travel plans have been disrupted." She said the disruption "is particularly difficult for people" as it comes during the holiday season.
London's Gatwick Airport says it expects disruption caused by drones to continue throughout Thursday and into Friday.
Flights at the major airport south of central London have been suspended since Wednesday night when two drones were reported above the airfield.
The airport statement says its runway remains unavailable because of the drones. It says all airlines have been advised to cancel flights up to at least 1600 GMT (11 a.m. EST).
It says anyone planning to fly Thursday or Friday should check with their airline before going to the airport.
The airport says it is working with airlines on plans to handle the many cancellations and delays once the runway is opened.
British police say they believe the flying of drones over Gatwick Airport is a deliberate act, but there are no signs it is related to terrorism.
Flights in and out of Britain's second-busiest airport have been suspended since Wednesday evening, disrupting the journeys of tens of thousands of passengers.
Supt. Justin Burtenshaw, the airport police commander, said: "We believe this to be a deliberate act to disrupt the airport. However, there are absolutely no indications to suggest this is terror-related."
Police say the first report of a drone over the airfield was made shortly after 9 p.m. (2100GMT) Wednesday and the last sighting around 8.45am on Thursday.
Police from two forces, backed by a helicopter, are scouring he area around the airport south of London for the drone operators.
London's Gatwick Airport remains shut while police and airport officials investigate reports that drones were flying in the area of the airfield.
Passengers traveling Thursday were advised to check the status of their flights before heading to the airport.
Gatwick first closed Wednesday night at around 9 p.m. (2100 GMT) when drones were sighted. It reopened at around 3 a.m. (0300 GMT) Thursday morning but shut down again in 45 minutes when drones were spotted.
Many incoming flights have been diverted to other destinations in Britain and continental Europe. The disruption is having a ripple effect on air travel as cancellations mount.
The drone sighting came near the height of the busy Christmas travel season.
Gatwick is a busy airport 27 miles (43 kilometers) south of central London.