Security checks for passengers boarding high-speed trains have been increased at three major Belgian stations since last month.
Belgian Home Affairs Minister Jan Jambon said on Wednesday that the checks have resulted in the screening of 17,000 passengers and 22,000 pieces of luggage. 
People travelling on high-speed international trains from Brussels, Antwerp and Liege are now randomly selected for security screenings to check for weapons and explosives. 
Since mid-July, 340 trains have undergone the additional scrutiny.
High-speed trains such as the Thalys are possible targets for terrorist attacks. In August 2015, there was an attempted attack on a train travelling from Brussels to Paris. The attack was foiled by passengers who were able to restrain the Moroccan man armed with a Kalashnikov.