Last week, police intercepted a van that was carrying around 150 kg of the drug.
The driver, a man in his thirties from Schoten near Antwerp, was detained.
On Monday, a total of six raids were carried out at addresses in Antwerp and the Limburg municipalities of Lanaken and Maasmechelen.
One man was detained in Lanaken and a further two men were detained in Maasmechelen.
Dutch police also searched premises across the border in the Netherlands.
220 kg of drugs and 8,500 euros in cash were confiscated.
The Dutch police also detained two suspects.
The police say that they are convinced that they have smashed a large-scale drug ring that has been active for a good number of years.