At least two children were among the four people killed Tuesday when a train hit a school minibus in northern Belgium, the country's deputy prime minister said.

"A tragic collision between a train and a school bus took place in Buggenhout this morning. Four people have been killed, including two children," Maxime Prevot wrote on X.

Prime Minister Bart De Wever posted that he was "deeply moved by the horrific accident ... My thoughts go out to the affected families."

Images from the scene in the Flanders region showed a badly damaged minibus lying on its side on a road next to a railway line, with tents set up by emergency workers around. The commuter train remained halted on the tracks.

Police spokesperson An Berger told Belgian media that seven children, a supervisor and a driver were aboard the minibus, adding that no one on the train was hurt.

"The impact was extremely violent," Frederic Sacre, a spokesman for Belgium's Infrabel rail agency, told AFP, adding that the train was traveling at 120 kph (75 mph).

"The minibus was thrown about 15 meters (50 feet) into a metal pylon," he said.

'Barrier closed'

Sacre said footage from the scene showed that the barriers at the crossing had been closed and a red light was showing at the time of the incident.

Belgian media reported that the pupils came from a school for children with learning disabilities.

Belgian Interior Minister Bernard Quintin expressed his deep sadness at the "tragic accident," writing on X that "my thoughts go out to the victims and their loved ones."

"I wish the injured much strength," he wrote, thanking the emergency services for their work.

European Commission chief Ursula von der Leyen joined in the stream of commiserations from politicians, saying she was "heartbroken" by the collision.

"My deepest condolences go out to the victims' families and their loved ones," she posted online.

"Today, Europe grieves with Belgium."