Drones sighted over submarine yard, power plant in Germany last week

Drones were sighted spying on critical infrastructure in Germany last week, including a submarine shipyard and a power plant, sources confirmed to dpa on Wednesday.

The interior minister of the northern state of Schleswig-Holstein, Sabine Sütterlin-Waack, is due to comment on the sightings in the state parliament in Kiel on Wednesday.

The state borders Denmark, where numerous drones have been sighted around airports in the past week, prompting temporary closures and serious concern from Danish politicians and NATO allies.

The incidents come after weeks of high tensions on NATO's eastern flank, prompted by recent incursions into the alliance's airspace over Poland, Romania and Estonia.

The latest sightings over Germany were first reported by Der Spiegel magazine, which said that drones flew over a power plant in Kiel, a university hospital and the ThyssenKrupp Marine Systems shipyard on Thursday.

The information has since been confirmed to dpa.

Some of the aircraft were reportedly in formation around a "mother drone."

According to the magazine, which cited security sources, the Kiel state parliament building and a refinery in Heide were among other targets.

Incidents involving drones have prompted debate in Germany over how authorities should respond to sightings in recent days, amid legal concerns and worries that shooting down the aircraft could lead debris to crash into populated areas.

Sütterlin-Waack said Schleswig-Holstein is currently strengthening its drone defence in coordination with other northern German states.

Carsten Breuer, the inspector general of the German military, plans to quickly deploy new weapon systems to defend against drones.

"One thing is clear to me: in the end, we will probably have to end up using drones against drones," the country's highest-ranking officer told dpa.