Belgium’s defense ministry is investigating after 15 drones were spotted Thursday night over the Elsenborn military base near the German border, according to local media reports.

The ministry told POLITICO on Friday it was still probing the incident. It’s currently not clear where the drones came from or who operated them, but reports said they flew into Germany after buzzing the base.

Belgian Defense Minister Theo Francken said Friday there is currently no concrete evidence linking the incident to Russia.

“That must be investigated. Personally, I think those drones are often an example of hybrid threats. This is a way to sow unrest. That has been Russia’s pattern for many years,” he said.

The Belgian sighting comes amid a wave of drone-related disruptions plaguing Europe’s airspace.

On Thursday evening, a separate incident over Munich Airport forced air traffic control to suspend operations, leading to the cancellation of 17 flights and affecting nearly 3,000 passengers.

“Munich Airport, in cooperation with the airlines, immediately took care of passenger care in the terminals. Camp beds were set up, blankets, drinks and snacks were handed out,” Munich Airport said in a statement Friday.

Bavarian Premier Markus Söder said Friday that police should be allowed to shoot down drones immediately. “[The state of] Bavaria must pass a fast-track law for this,” the Christian Social Union politician wrote in a post on X.

Airport officials added that 15 incoming flights were diverted to Stuttgart, Nuremberg, Vienna and Frankfurt.

In recent weeks, airports in Denmark and Norway have also suspended operations after drones were spotted in their airspace, fueling debate among European leaders over the feasibility of a “drone wall” on the eastern flank to guard against Russian belligerence.

In the most serious incident, nearly two dozen Russian attack drones crossed into Poland sparking a multimillion-euro emergency response from allied weapons systems.

British concern

Analysts are worried by the difficulty of responding to these incidents.

A recent assessment of threats to the U.K. in the Strategic Defense Review gave high importance to the development of counter-drone technology — but gave less space to the risk currently faced in British airspace.

Robert Tollast, a researcher at the defense think tank RUSI, said police and military authorities in the U.K. were “increasingly concerned” about drones, but their main concern was over the type of quad-copter which disrupted Gatwick Airport in 2018 rather than the larger drones seen in Europe recently.

“If you’re looking at defending an airport from quad-copters, it’s really difficult,” he added. Private companies and the police have been exploring a number of ways to detect small drones, which have developed considerably since 2018 but are still expensive to purchase.

Drone technology is evolving at a “worrying” pace, Tollast said, and “U.K. military and U.K. police need to be training on these situations on a very regular basis but at the moment, it’s slow going.”

Ferdinand Knapp contributed to this report.

This story has been updated.