London’s Gatwick Airport reopened on Friday after a saboteur wrought 36 hours of travel chaos for over a hundred thousand Christmas travelers by using drones to play cat-and-mouse with police snipers and the army.

After the biggest disruption at Gatwick, Britain’s second busiest airport, since a volcanic ash cloud in 2010, Gatwick said around 700 planes were due to take off on Friday, although there would still be delays and cancellations.

Britain deployed unidentified military technology to guard the airport against what Transport Secretary Chris Grayling said were thought to be several drones.

“I think passengers are safe,” Grayling said. “This kind of incident is unprecedented anywhere in the world.”

The motivation of the drone operator, or operators, was unclear. Police said there was nothing to suggest the crippling of one of Europe’s busiest airports was a terrorist attack.

Gatwick’s drone nightmare is thought to be the most disruptive yet at a major airport and indicates a new vulnerability that will be scrutinized by security forces and airport operators across the world.

The army and police snipers were called in to hunt down the drones, thought to be industrial style craft, which flew near the airport every time it tried to reopen on Thursday.

DETECTOR GADGETS

The perpetrator has not yet been detained, police said, and no group has claimed responsibility. British officials will meet on Friday to discuss the situation. The defense ministry refused to comment on what technology was deployed.

Flights were halted at 2103 GMT on Wednesday after two drones were spotted near the airfield. The disruption affected at least 120,000 people on Wednesday and Thursday, with thousands more to be disrupted on Friday.

After a boom in drone sales, unmanned aerial vehicles have become a growing menace at airports across the world.

In Britain, the number of near misses between private drones and aircraft more than tripled between 2015 and 2017, with 92 incidents recorded last year.

Flying drones within 1 km (0.6 mile) of a British airport boundary is punishable by five years in prison.

The drone sightings caused misery for tens of thousands of travelers who were stranded at Gatwick, many sleeping on the floor as they searched for alternative routes to holidays and Christmas family gatherings.