German security forces have "indications" that Russian secret services spied on Ukrainian soldiers who are in Germany to receive training on Western weapons, Spiegel magazine reported Friday.
German military forces have spotted suspicious vehicles outside two sites where Ukrainian recruits were being trained.
Small drones were also used to fly over the training sites before quickly disappearing, Spiegel said, without citing its sources.
The two affected locations are Idar-Oberstein in the western state of Rhineland Palatinate where Ukrainian soldiers are being trained to use the tank howitzer 2000 and Grafenwoehr in Bavaria where the US army is teaching Ukrainians to use Western artillery systems.
Security sources also believe that Russian services used scanners in a bid to access mobile phone data of Ukrainian soldiers, said the magazine.
Germany has put several suspects on trial for spying for Russia.
Last year, a German court sentenced a Russian man to life in prison for shooting dead a former Chechen commander in a Berlin park in broad daylight, a murder prosecutors say Moscow ordered.
A German man is currently on trial for allegedly passing information to Russian intelligence services while working as a reserve officer for the German army.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)