Drone sightings at Germany's Munich airport have led to the cancellation and diversion of dozens of flights on the eve of a national holiday, leaving nearly 3000 passengers stranded, and authorities say they are investigating the incident. A flight from Bangkok was the first of the day to land after 5am on Friday, according to the airport's website. The airport said several drone sightings late on Thursday evening had forced air traffic control to suspend operations, leading to the cancellation of 17 flights and disrupting travel for nearly 3000 passengers, who were provided with camp beds, blankets and food. Authorities have not publicly blamed anyone for the Munich drone incident, but some European officials have suggested Russia was behind other recent airspace violations. But Russia also tries to sow division and anxiety in our societies," European Commission chief Ursula von der Leyen said on Wednesday.