dozens of flights were cancelled and thousands of passengers left stranded on the eve of a German national holiday and the famous Oktoberfest. A week earlier, Copenhagen and Aalborg airports were closed following sightings of unmanned aerial systems in Danish airspace. In the month since a swarm of Russian drones violated Polish airspace — three were shot down — a rash of similar incidents has been reported across Germany, the Baltic and Nordic countries, often over power plants and military bases.
Denmark's Aalborg airport was closed due to drones in its airspace, local police said early on Thursday, two days after the country's main Copenhagen airport was shut over drone sightings that rattled European aviation. Danish national police said the drones followed a similar pattern to the ones that had halted flights at Copenhagen airport for four hours a few days earlier.
