LONDON — The British Army has been called up to combat rogue civilian drones that have closed the country’s second busiest airport since Wednesday evening for more than 24 hours.

UPDATE (Dec. 21, 6:54 a.m. EST):

“Gatwick’s runway is now available and aircraft are arriving and departing,” the airport’s website says. “We are, however, expecting knock-on delays and cancellations to flights. If you are due to travel from Gatwick today, we strongly recommend that you check the status of your flight with your airline before departing for the airport.”

UPDATE (Dec. 20, 6:55 p.m. EST):

Sightings of drones are continuing at Gatwick Airport. Numerous further sightings have been reported throughout the day, one as recently as the evening of Dec. 20.

Having rejected the idea of shooting down any drones, the government’s position may now change if the opportunity arises to do it safely, the BBC is reporting.

Police are now saying there have been 50 drone sightings.

STORY (Dec. 20, 3:53 p.m. EST):

The Ministry of Defence confirmed the deployment in a Thursday tweet, but the MoD has not provided details of the unit involved or the equipment deployed.

“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," Defence Secretary Gavin Williamson said.

The closure of Gatwick Airport has resulted in massive disruption with no inbound and outbound flights for a day. Situated south of London, the airport is the country’s second busiest after Heathrow and last year handled more than 45 million passengers.

The closure of the airport followed reports of two drones flying in and around the airfield at approximately 9 p.m. on Dec. 19.

The police believe the drones were of an “industrial specification” and do not believe it was a terrorist-related incident.

Little has been published about the equipment deployed by the British government to protect sensitive sites around the country as the threat from drones intensifies. This is thought to be the first time the government has publicly acknowledged the military’s deployment to specifically counter a drone threat.

The British did, however, announce in August that it had spent $20 million to urgently acquire an anti-drone systems from Israeli company RADA Electronic Industries.

In a statement at the time, the Israeli firm said it expected to complete delivery of equipment by the end of this year. There is nothing to suggest the system, known as the Drone Dome, has been deployed, but its urgent procurement does signal the growing threat that small UAVs pose to civil and military sites.

In a statement announcing the deal, RADA said earlier this year it’s system provides “360-degree surveillance and detects the drones at distances of 3-5 kilometers. Signal intelligence system along with electro-optical sensors, provide additional layers of threat classification and identification, while RF jamming provides the soft-kill layer of this solution."

Gatwick Airport boss Stewart Wingate said the incident raised long-term strategic concerns over the threat posed by civilian drones to key infrastructure in Britain.

“Although not for today, these events obviously highlight a wider strategic challenge for aviation in this country, which we need to address together with speed — the aviation industry, government and all the other relevant authorities. It cannot be right that drones can close a vital part of our national infrastructure in this way," Wingate said.

Andrew Chuter is the United Kingdom correspondent for Defense News.

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