UK police say they have made two arrests in connection with criminal drone activity at Gatwick Airport [abc.net.au], and urged the public and passengers around the airport to remain vigilant. Britain's second-largest airport reopened on Friday after a mystery saboteur wrought 36 hours of travel chaos for more than 100,000 Christmas travellers by using drones to play cat-and-mouse with police snipers and the army. The defence ministry refused to comment on what technology was deployed, but drone experts said airports needed to deploy specialist radar reinforced by thermal imaging technology to detect such unmanned flying vehicles.