He said authorities were continuing to actively follow lines of investigation to catch those responsible for the most disruptive incursions from unmanned aerial vehicles seen at any major airport.

A damaged drone had been recovered close to the perimeter of the airport, he said, and it was being forensically examined for clues about whether it was controlled from afar or by somebody in the vicinity.

No group has claimed responsibility for the disruption.

"We have kept an open mind throughout and that is still the case with regards to the motivation behind these incidents," he said.

The drones were spotted at Britain's second-largest airport on Wednesday evening, forcing it to close its runway in the run up to Christmas. Every time the airport sought to reopen the runway on Thursday, the drones returned.

Authorities finally regained control over the airfield after the army deployed unidentified military technology to guard the area, reassuring the airport that it was safe enough to fly.

The drones caused misery for travellers, many sleeping on the airport floor as they searched for alternative routes to holidays and Christmas family gatherings.

Airlines operating at Gatwick, which is located south of London, include easyJet, British Airways and Norwegian.

The airport said on Sunday it was offering a reward of £50,000 ($70,000) for information leading to the arrest and conviction of those responsible.

It said it was expecting to operate a full schedule of 785 flights on Sunday, although a small number of delays and cancellations were possible as the airport fully recovered.

Reuters