The BBC is reporting the sightings as a 'drone attack' and the airport has remained closed to traffic since Wednesday night, leaving thousands of passengers stranded at the airport.
The airport said that 110,000 passengers were due to fly on 760 flights on Thursday in the busy build up to the Christmas holidays.
Earlier today it issued the following statement: "Gatwick Airport’s runway remains closed and all flights are currently suspended following reports of drones flying over Gatwick’s airfield last night and this morning.
"There is significant disruption at Gatwick today as a result of what appears to be a deliberate attempt to disrupt flights.
"We are extremely disappointed that passengers are being affected by this,especially at such an important time of year. We are prioritising the welfare of those at the airport by deploying staff into our terminals to look after people as best we can.
"We are working hard with our airlines to get information to passengers but would advise anyone booked onto flights from Gatwick, or meeting arriving passengers, not to travel to the airport without checking the status of the flight with their airline or on our website first.
"We apologise for the continued inconvenience, but the safety of all passengers and staff is our first priority."
Commenting on the closure of London Gatwick Airport due to a drone incident, chief executive of the Airport Operators Association, Karen Dee, said: “While the closure of Gatwick Airport caused by a drone operating illegally near the airfield is ongoing, staff at Gatwick are working hard to resolve this situation with the police and are supporting the passengers currently at the airport.
“At moments like this, we work together as an industry to put the passengers’ safety first. Airports across the UK are supporting Gatwick by taking diverted aircraft and helping passengers who were due to fly to Gatwick today.
“We urge passengers to check with their airline before travelling to their airport if they were due to fly to or from Gatwick today.
“As this incident shows, drones can cause major disruption to passengers, who were looking forward to well-deserved Christmas breaks, as well as major financial damage to the UK economy. That is why flying a drone near an airfield or endangering aircraft with a drone is a criminal offence with penalties of up to five years in jail.”
At 13.45 today, the airport admitted that the travel disruption would last for the rest of the day and even continue into tomorrow.
A media statement reads: "Gatwick Airport’s runway remains unavailable because of drone sightings.
"We have advised all airlines to cancel flights up to at least 16:00 this afternoon, while keeping the situation under constant review. There is significant disruption at Gatwick and our terminals are extremely busy.
"We are prioritising the welfare of passengers during this very difficult time, and have teams across the airport looking after them as best we can.
"We anticipate disruption to continue throughout the day and into tomorrow.
"Any passengers due to fly today or tomorrow should not set off for Gatwick without checking flight information with their airline.
"We are extremely disappointed that what appears to be deliberate action is affecting journeys at this important time of year.
"We are working tirelessly with our airlines to put plans in place to recover our operation once given the go ahead that our runway can re-open.Once again we apologise for the continued disruption. Safety is our absolute priority.