UK police have arrested two individuals in connection with flight disruptions at London Gatwick Airport. The pair, a 47-year-old man and a 54-year-old woman were arrested late on Friday, according to the Sussex Police.

Air traffic at Gatwick, England’s second largest airport, was disrupted when a drone was spotted flying in the area on Wednesday, prompting the airport to suspend flights through Friday. Flights were diverted to other airports, and authorities ended up bringing in the British Army, which media reports say set up an Israeli-built drone defense system called a “Drone Dome,” designed to intercept the device’s radio signals. Flights resumed at the airport on Friday.

Sussex Police did not identify the individuals, other than to say that they were being held on “suspicion of disrupting services of civil aviation aerodrome to endanger or likely to endanger safety of operations or persons,” and that the investigation was ongoing. According to The Guardian, authorities aren’t investigating the incident as a terrorism incident, but say that “an environmental protest was a possibility.”