Denmark’s Copenhagen Airport—Scandinavia’s busiest—was forced to ground all flights on September 22 after 2–3 large, non-commercial drones violated its airspace. The sudden shutdown led to the diversion of over 30 flights as police scrambled to identify the drones, amid fears of Russian provocation. This incident marks the third reported airspace incursion involving NATO nations in just two weeks. Similar alleged Russian drone or jet violations were recently reported by Poland and Estonia. Watch the video for more.