Armored vehicles mobilized just outside the town of Kortrijk, or Courtrai, in western Flanders. Belgian prosecutors said that the raids were connected with the terror plot foiled in France last week.
Thursday's raid on the outskirts of Kortrijk, a Belgian town near the French border, was reportedly connected toReda Kriket, the man charged on Wednesday in France with plotting an "imminent" terror attack.
French and Belgian security services cooperated in the operation.
"There is a raid in process connected with the Kriket case," Belgian federal prosecutor Eric van der Sypt told the AFP news agency, mirroring information elsewhere in Belgian media. "It's happening in Marke, in the town of Courtrai," he said, using the Francophone name for the town.
The site is close to the E17 highway, south of the Flemish town.
Images showed military and police vehicles present outside the rural Flemish home, having sealed off the area. Some soldiers searched a forested area nearby with the aid of metal detectors and canine units.
It was not immediately clear if the raids had yielded any arrests or seizures.
Reda Kriket, a 34-year-old French national,was arrested on March 24 in Paris.
He's already been convicted on terror-related charges in Belgium, and is suspected of spending time in the ranks of the so-called "Islamic State" (IS) in Syria. In the apartment he was occupying, police found fuses, automatic weapons, handguns and the TATP explosives seemingly favored by IS. He was also in possession of five false passports.
Also in connection with the Kriket case, security forces in the Netherlandsarrested 32-year-old Anis Bahri in Rotterdam over the weekend.
The French national's apartment held some 45 kilos of 7.62 caliber ammunition, suitable for Kalashnikov assault rifles.