UK's Gatwick Airport reopens after drone disruption

London's Gatwick Airport has reopened after a 36-hour halt in operations due to drones spotted over the runway on Wednesday night.

The airport located just outside greater London in the south is a gateway for millions of passengers.

A small number of flights arrived and took off on Friday but officials say “additional mitigating measures” are in place.

Up to 100 flights of the more than 750 scheduled flights could be cancelled due to the knock on effect.

Chris Woodroofe, a chief operations officer, said police are trying to find the drone operator.

On Thursday, more than 100,000 passengers were affected as flights could not resume, while incoming flights were diverted to Luton, Heathrow, Stansted and Manchester.

Sussex Police said it was not a terror-related incident but a "deliberate act".

Defence Secretary Gavin Williamson confirmed yesterday the military personnel have been called in to support police.

"The armed forces have a range of unique capabilities and this isn't something we would usually deploy but we are there to assist and do everything we can so that they are in a position to open the airport at the earliest opportunity," Williamson said.

The drones were first spotted over the runways Wednesday night. They brought all outbound flights to a halt. All incoming flights have been redirected to other airports, including Paris and Amsterdam.

Gatwick is one of a few big air travel hubs near London and a knock on effect is feared if the flights are not back to normal soon in one of the busiest times of the year.

Almost 3 million passengers are expected to use the airport in the upcoming festive period until the New Year.