Police in Brussels arrest six suspects in multiple raids, the broadcaster VRT reports.
No information about the identity of the detainees was released. Police raided locations in the Brussels neighbourhoods of Schaerbeck and Jette, Belga says. Special police units were involved in the operations.
The VRT report was confirmed by the state prosecutor's office to the Belga news agency.
In an earlier raid in Schaerbeck following Tuesday's bombings police found a bomb workshop where terrorism suspects are believed to have made explosives.