Unidentified drones spotted near NATO base housing U.S. nuclear weapons in Belgium as flights from Brussels and Liège temporarily suspended

On the evening of Nov. 4, unidentified drone sightings were reported near Belgium’s Kleine-Brogel and Florennes air bases, as well as at airports in Brussels and Liège. NATO’s Kleine-Brogel base is one of several sites in Europe where U.S. nuclear weapons are stored, according to a report by German outlet Deutsche Welle. The Belgian news agency Belga reported that local residents spotted at least six drones near the base.

Brussels Airport was temporarily closed, remaining out of service throughout the night, according to a report by The Guardian. Dozens of flights were cancelled. Service at Liège Airport was also suspended.

Gert Klueckers, the mayor of Diest, wrote on Facebook that four additional drones were seen overnight above the Schaffen air base. Belgium’s National Security Council is scheduled to meet on Nov. 6 to discuss the incidents.

Interior Minister Bernard Quinten suggested that Russia — or, possibly, an “enthusiast” — could be behind the drone launches. He said Belgium “cannot tolerate disruptions to our airports caused by unauthorized drone flights” and called for “a coordinated, nationwide response.”

Defense Minister Theo Francken said the authorities believed the drone sightings to be “intentional and disruptive,” with “semi-professional, professional large drones” flying “in formation.”

He told lawmakers that the country is considering invoking Article 4 consultations within NATO, though no decision has been made.

Article 4 states that member nations “will consult together whenever, in the opinion of any of them, the territorial integrity, political independence or security of any of the Parties is threatened.”

The clause has been invoked only nine times in NATO’s history, including twice this year, when Poland and Estonia called for consultations in September after incidents in their airspace.

This is not the first time Belgium has seen such activity. On Nov. 2, unidentified drones flew over the Kleine-Brogel base. At the time, Francken said the aircraft were flying at high altitude and appeared to be deliberately operating in the vicinity of the NATO installation.

Unidentified drones have repeatedly disrupted European airports and appeared near military facilities in Germany, Denmark, and Norway. Authorities in those countries have also suspected Russian involvement. In October, Germany’s government approved amendments allowing federal police to shoot down suspicious drones.