Brussels (AFP) - Belgian police on Monday briefly detained six people in connection with a foiled attack last year on a high-speed train travelling from Amsterdam to Paris, prosecutors said.
They were later released without charge after "simple verifications", the federal prosecutor's office told AFP in an email.
On August 21, Moroccan Ayoub El Khazzani boarded the train in Brussels armed with a Kalashnikov and other arms but was overpowered by a group of Americans and a Briton as he opened fire.
While he remains in custody, a judge leading the investigation into the attack ordered six raids carried out Monday in the Brussels area, including four in the Molenbeek district, considered a jihadist hotbed.
"Six people were detained for questioning," prosecutors said, adding that no weapons or explosives were found in the raids.
It added that the investigating judge will decide in the next few hours whether to keep them in custody.
Belgian authorities on Saturday charged three men with "attempted terrorist murder" after raiding dozens of homes in raids linked to a reported threat to fans during a Euro 2016 football game.
Raids were carried out across Belgium, including Molenbeek, where Khazzani stayed with his sister before boarding the Amsterdam-Paris Thalys train.
Molenbeek has also been the focus of the investigation into the March 22 Brussels bombings, which left 32 people dead, and the November 13 Paris attacks, which killed 130 people.