"I have some ideas, but I'm going to be cautious," he added.
Drones were also spotted flying above other military air bases - the Leopoldsburg, in central Limburg province, and Marche-en-Famenne in the south-east of the country.
VRT reported over the weekend that drones were also seen close to coastal Ostend and Antwerp's Deurne airports.
It marks the latest incident involving drones disrupting European airspace in recent months.
In October, unconfirmed drone sightings forced Germany's Munich airport to suspend operations twice in 24 hours.
The month before, Denmark said drones flown over its airports appeared to be the work of a "professional actor".
At the time, Danish Defence Minister Troels Lund Poulsen said there was no evidence to suggest Russia was behind the incursion.
The Russian embassy in Copenhagen denied "absurd speculations" of its involvement.
Also in September, Estonia and Poland requested a consultation with other Nato members, after around 20 Russian drones crossed into Poland and Russian MiG31 jets entered Estonian airspace.
Russia denied violating Estonia's airspace and insisted the Polish incursion was not deliberate.
The European Commission has since proposed four defence projects, including a counter-drone system, as part of plans to get the continent ready to defend itself by 2030.