Passengers wait in the South Terminal building at Gatwick Airport, after the airport reopened to flights following its forced closure because of drone activity, in Gatwick, Britain, December 21, 2018. REUTERS/Toby Melville

(Reuters) - British police have shortlisted potential culprits in the drone incident that has caused chaos and delays at London’s Gatwick Airport, the Telegraph newspaper reported on Friday.

The perpetrator had circled the drone around the airport building and flashed its lights, the report said, adding that a description of the drone by witnesses has enabled experts to determine the model of the machine.

The perpetrator has not yet been detained.

Gatwick, Britain’s second-busiest airport, was reopened on Friday after being forced to close for 36 hours this week, stranding more than 100,000 Christmas travelers, when a mystery saboteur used drones to play cat-and-mouse with police snipers.