"President António José Seguro sent a message of condolence to King Philippe of Belgium, after learning, with deep dismay, of the tragic collision," reads a note published on the official website of the Presidency of the Republic.

The Head of State, on his own behalf and on behalf of the Portuguese people, expressed "full solidarity with the pain and mourning of the Belgian people, offering heartfelt condolences to the bereaved families and wishes for a speedy recovery to the injured."

Four people who were on the minibus, including two children, died in the accident, which occurred when the vehicle was crossing a level crossing in the municipality of Buggenhout, in the Belgian region of Flanders.

There were five other children in the vehicle, who were hospitalised.

Belgian Federal Police spokeswoman An Berger said the collision occurred shortly after 7 am Lisbon time and that the level crossing barriers were down.

According to the spokeswoman, no one on the train was injured, although one person was treated for shock.