Authorities in Schleswig-Holstein are investigating unexplained drone flights near the Danish border.

A series of coordinated drone flights over northern Germany on Thursday has prompted a security investigation after unmanned aircraft were seen above multiple sensitive locations, including a parliament building, a naval yard, an energy facility and the Academic Medical Center of Kiel. Additional sightings were reported over military sites near Sanitz in the neighbouring state of Mecklenburg-Vorpommern.

Schleswig-Holstein state minister Sabine Sütterlin-Waack confirmed that police are examining flight paths to establish where the drones came from and where they went. Officials said the aircraft appeared to operate as a network with a larger “mother drone” and seemed to be mapping critical infrastructure. The origin of the devices is unknown, and investigators have not determined whether they are linked to drones reported over Denmark the previous week.

Germany’s interior minister, Dobrindt, described the flights as a threat and called for the creation of a dedicated drone defence centre. In Berlin, a proposal to extend military powers to shoot down hostile drones has previously been discussed but never put to a vote after the government collapsed, leaving a gap in enforcement that officials say needs to be addressed.

The reports follow earlier allegations of Russian reconnaissance drones operating over Germany to monitor US military supply routes to Ukraine, underscoring concerns about espionage and critical infrastructure security. While no direct connection has been established, the latest incidents highlight the difficulty of attribution and the potential vulnerabilities of civilian and military sites.

Across the border, Denmark temporarily closed its airspace and the airports in Copenhagen and Aalborg during last week’s drone sightings. European Union leaders are meeting in Copenhagen to discuss counter-drone measures, with a temporary ban on civilian drone flights in the city during the summit. Authorities in both countries have urged the public to report suspicious aerial activity.