The operation came in the wake of official shock over a radicalised soldier, Jurgen Conings, who in June sparked a huge month-long manhunt after he went missing with military weapons and threatened to target state officials and a high-profile virologist.

Conings's body was later found in a forest following his suicide by firearm.

Wednesday's raids stemmed from the lack of monitoring for radicalisation in Belgium's military revealed by the Conings case. The defence ministry has launched several internal inquiries to identify such problems before they escalate.

The searches were carried out on the three barracks and eight home addresses of soldiers.

"The potentially implicated individuals are suspected of distributing or making available to the public messages intended to incite commission of a terrorism-related crime," the prosecutor's office said in a statement.

It said the probe was looking at those "suspected of links to the extreme right".

A Belgian media outlet, RTBF, said Wednesday's operation was not aimed at making arrests but rather collecting evidence for analysis.