BERLIN

Multiple drones were spotted over Germany's northern state of Schleswig-Holstein overnight, prompting an investigation into possible espionage activities amid growing concerns about airspace security in the Baltic region.

Schleswig-Holstein’s interior minister confirmed on Friday that officials are treating the incident as a potential surveillance operation, coming just days after similar drone sightings in neighboring Denmark.

"We are certainly investigating every suspicion of espionage and sabotage in Schleswig-Holstein and remain extremely vigilant in this area," Interior Minister Sabine Sutterlin-Waack said in a statement.

Authorities declined to specify how many drones were observed or their exact locations, but confirmed it is in "intensive and ongoing communication" with federal authorities and the German military. Police have strengthened drone defense measures in coordination with other northern German states.