The Belgian police searched more than two hundred houses and other buildings early on Tuesday, especially in Antwerp.
The police have cracked a communications service of the underworld, Belgian media report. That would have put the police on the trail of drug traffickers and people who facilitate their practices, such as tipsters and money launderers.
Last year, the police managed to access the encrypted messaging service Sky ECC, writes De Morgen, among others. It is very popular with criminals because they believe they can communicate with it without prying eyes.
Agents have raided, among other things, the company behind the communication service and sellers of the app and suitable telephones, insiders told De Morgen. House searches were also allegedly carried out at three lawyers.
More than 1500 officers took part in the Belgian part of the international police operation. They also included special forces. Whether people have been arrested or cases seized is not yet known.
The port of Antwerp is a notorious hub of the international drug trade.