Infrabel, which manages Belgian rail infrastructure, told AFP that two trains — an international Thalys service and a French TGV — had been halted mid-route.

These services were restarted two hours later, as huge crowds built up on platforms at Brussels’ Midi Station, but passengers were warned of knock-on delays throughout the day.

In addition to the Thalys route, which connects Amsterdam, Brussels and Paris, the Eurostar service from the Belgian capital to London also faced disruption and at least one cancellation.

“Traffic has restarted, but there will be multiple delays throughout the day on international services,” an Infrabel spokesperson said.

Two Thalys services from Amsterdam to Paris via Brussels have been cancelled, the rail company said. There will also be long delays on some services to the German town of Dusseldorf and to Schiphol airport.

A passenger booked to travel on a Eurostar train from Brussels to London told AFP that he had been informed that it was cancelled and offered a chance to rebook or receive a refund.

“We have a plan for winter, including infrastructure inspections and de-icing measures, but there’s no such thing as zero risk,” the Infrabel spokesperson said.