Belgium's federal prosecutor's office confirmed it has launched two investigations following recent drone sightings in national airspace.
"As soon as drones are detected, we investigate their origins," said spokesperson Yasmina Vanoverschelde.
"Initially, we contact local police and prosecutors. If there are indications of espionage or interference, it will be federalised."
One investigation concerns drones seen over the Kleine-Brogel air base last weekend, while another focuses on drones spotted in Elsenborn on 3 October.
No federal file has yet been opened for the most recent drones reported on Tuesday evening.
