Six people have been arrested in connection with the 2015 failed terror attack on a high-speed train between Amsterdam and Paris.
A man with a Kalashnikov wounded two people before being overpowered by passengers including two off-duty US servicemen and a British businessman on the train in August last year.
The arrests come after three men were detained and charged with plotting a terror attack in raids over the weekend on properties across Brussels. Belgian media reported the men planned to attack fans watching the Euro 2016 football tournament in France.
In Monday's raids (20 June) six homes in the greater Brussels area were searched and six people detained, Reuters reported. No weapons or explosives were found.
An investigating judge will decide whether the three will be detained further.
Four of the men who foiled the train attack were subsequently awarded France's highest honour, the Legion d'honneur. The alleged perpetrator, Ayoub el Khazzani, remains in police custody ahead of his trial on terror charges.
Belgium is currently on high alert after 32 people were killed in attacks on Brussels airport and a metro station in the city on 22 March by members of an Isis terror cell.
The cell is also linked to the 13 November terror attacks in Paris, in which 130 people were killed.