LONDON — British police have released two people without charge after they were arrested in connection with unauthorized drone activity that shut down air traffic at the country's second busiest airport during the height of holiday travel season.

A 47-year-old man and 54-year-old woman had been arrested late Friday in a town not far from the airport.

“Both people have fully co-operated with our enquiries and I am satisfied that they are no longer suspects in the drone incidents at Gatwick," Sussex police chief Jason Tingley said in a statement on Sunday.

Police will now resume their hunt for suspects, with the public once again in the dark about the identity and motive of those responsible for the disruption.

Officials have previously said there was no suggestion that terrorism is involved.

“Our inquiry continues at a pace to locate those responsible for the drone incursions, and we continue to actively follow lines of investigation," Tingley added.

Investigators also recovered a damaged drone close to the airport on Saturday. "Obviously we'll be doing everything we can with regards to forensically examining that drone," Tingley said.

Drones began buzzing at the airport Wednesday night, leading to a 36-hour closure that left thousands scrambling to re-arrange their holiday plans.

A drone sighting Friday led to a second, brief shutdown of the airport — despite the presence of military and police snipers mobilized to shoot it down. Authorities were concerned the drones could disrupt airplane flight paths, disable jet engines or worse.

Gatwick was plagued by long lines and flight delays Saturday but no new drone sightings, allowing British officials to hope the worst was over. Flights are now operating normally.

"The military measures we have in place at the airport have provided us with reassurance necessary to re-open our airfield," airport officials tweeted.

Those measures include an Israeli-developed radar system that can track drones and jam their signals, England's Sky News reported.

The persistent drone crisis at Gatwick, which is located 30 miles south of London and serves 4 million passengers a year, has had ripple effects throughout the international air travel system.

The airport is now offering a reward of over $60,000 for information leading to the arrest and conviction of those responsible.