Two raids have taken plane in the Molenbeek district in Brussels. Authorities have warned of an increased likelihood of a terrorist attack on European soil by fighters returning from the Middle East.
Police in Belgium arrested four people in connection with a terrorism investigation into a 2015 attack on a high-speed Paris-bound Thalys train, according to prosecutors.
Authorities raided at least six properties in Brussels and southern Belgium. “Four people were taken in for questioning,” prosecutors said in a statement.
Read more: ‘Islamic State’: Will it survive a post-caliphate future?
At least two of the raids took place in the Belgian capital’s Molenbeek district. “Neither explosives nor weapons were found” during the raids on Monday, prosecutors added.
Investigating judges are expected to decide later whether to keep the suspects in detention.
Wave of attacks
A bloodbath was avoided in August 2015 when passengers – including two off-duty US soldiers – subdued Ayoub el-Khazzani, who was armed with a Kalashnikov, a pistol and box cutter.
Belgium and France have been on high-alert following a series of deadly terrorist attacks. In November 2015, the “Islamic State” (IS) militant group claimed responsibility for devastating attacks across Paris that left 130 people dead.
Read more: EU introduces new measures to combat ‘low-tech’ terrorism
Months later, IS militants launched attacks on Brussels Airport and a central subway station, leaving 32 people dead.
With IS losing territory in the Middle East, authorities have warned of the growing possibility of attacks on European soil with fighters making their way to their home countries in Europe.