The surveillance drones are suspected of gathering information that can be used by Russia's military and in Russian sabotage.
"Outright espionage", comments Seth Jones at the think tank CSIS on the matter to The New York Times. Russia is trying to get information about which companies manufacture weapons for Ukraine and how they are then sent to Poland and on to Ukraine, notes Jones. When the Russians know which weapons are incoming, they can gain an advantage on the battlefield.
Above all, the drones have been noted over the German state of Thüringen, which the German Wirtschaftswoche has also reported on. Flights near military bases pose a particular security risk, says a spokesperson for the German military to the newspaper.
According to Wirtschaftswoche, at least some of the drones have been manufactured in Iran. The German intelligence service suspects that some of them have originated from ships in the Baltic Sea.
American and European military officials are increasingly worried about the flights, according to information to The New York Times. American officials confirm the matter to the newspaper, but state that they have had difficulty tracking the drones in question.
