Germany investigating possible Russian involvement in drone flights over nuclear power plant in country's north – Bild

Prosecutors in the northern German city of Flensburg are investigating an incident involving unidentified drones flying over a shutdown nuclear power plant.

Bild reports that since at least 8 August, drones have been flying at high speed over the area where the shutdown nuclear power plant, liquefied natural gas terminal and chemical plants are located in Flensburg.

A drone flying at over 100 km/hour was spotted in the sky above the nuclear power plant late on 20 August. An internal police report stated that "the no-fly zone had been violated several times".

The most recent drone incident occurred on 22 August, prompting police in Schleswig-Holstein, the federal state where the city is located, to put some officers on alert.

Special services believe that the drones over Flensburg may have been launched by Russian agents from ships in the North Sea for sabotage purposes. They suspect the drones are Orlan-10 models, capable of a range of 500-600 kilometres and speeds over 100 km/h.

Senior Flensburg prosecutor Bernd Winterfeldt confirmed to Bild that a tentative investigation is underway "on suspicion of sabotage activities linked to multiple drone flights over critical infrastructure in Schleswig-Holstein".

In recent months, Germany has reported multiple attempts to sabotage its infrastructure and military facilities.

In addition, unidentified drones were spying on Ukrainian soldiers during training in Germany. This year, two German-Russian citizens were detained on suspicion of preparing a sabotage at a US base in Bavaria.