Belgian police were conducting an operation targeting people-traffickers. They hope to map out the networks and routes used and deter migrants from embarking on a dangerous and illegal journey to the UK.
27 men and a woman were held: 10 Eritreans, 17 Sudanese and one Ethiopian. Eleven of the 28 claimed to be minors.
Checks mainly targeted trains running between Brussels and Antwerp. Police say many are the migrants using public transport to leave Brussels and head for Antwerp and other destinations. The migrants arrive at Antwerp Berchem or Antwerp Central and then take a bus or tram to motorway carparks where they try to board lorries bound for the UK.