Two drones have reportedly been seen flying over Gatwick Airport since 9 pm GMT on Wednesday, 19 December, prompting flights to be delayed and a major investigation into the incident by the Sussex Police.

More than 50 sightings of the unmanned devices have been made since 9 pm on 19 December, when the airport was first closed, RTE reported, quoting Detective Chief Superintendent Jason Tingley of Sussex Police. He reportedly stated that shooting the drone down was an option as other strategies failed. 

"We will do what we can to take that drone out of the sky and remove that disruption so we can get Gatwick back to normal. One of the options is to use firearms officers if that presents itself — they have been out on the ground today and that's a consideration and a tactical option that's open to us.

There are a number of factors in terms of range, the height of the drone and the likely impact on us firing at the drone but that is a tactical option open to the gold commander who will make a decision based on the information available to them at the time", Tingley told reporters.

A Gatwick Airport representative has declined to say whether the drones would be shot down, but announced that they have put in additional measures against the drones.

The airport has reopened its runway and resumed flights after the suspension.

"Gatwick's runway is currently available and a limited number of aircraft are scheduled for departure and arrival", the airport said on its website.

According to the airport flight information, several planes have already departed from the runaway.

According to Tingley, the police were looking into a theory that the "drone had been modified, with the intent of causing disruption", and have been looking through CCTV footage to classify the make and model. 

The airport reopened at 3 am local time on 20 December but closed 45 minutes later as the drones returned. 

Some 120,000 people have reportedly suffered from the stalemate, being unable to fly to their destinations due to the drones that have repeatedly been spotted over the runway.