At least four people, including two teenagers, died after a train collided with a school bus in the Belgian town of Buggenhout on Tuesday morning.
Belgium's interior minister Bernard Quintin expressed grief over the accident, saying his thoughts go out to the victims and their loved ones.
The collision happened at a level crossing in the northern Flanders region, with the impact described as 'extremely violent' by Infrabel's spokesman Frederic Sacre.
EU chief Ursula von der Leyen said she was 'heartbroken' by the crash, offering her condolences to the victims' families and their loved ones.
