At least three people were dead after a passenger train hit a freight train near the Belgian city of Liege, the Belga news agency reported early Monday.
The number of victims could rise as the wreckage is searched and the injured treated, Saint-Georges-Sur-Meuse Mayor Francis Dejon told the agency.
Nine people were hospitalized, and a further 27 treated briefly at the scene. "We were very lucky that there were not more victims," Dejon was quoted as saying.
The six-carriage passenger train was carrying around 40 people at 90 kilometres per hour when it hit the back of a freight train, he said.
National train operator SNCB said the front two carriages derailed.
The cause of the accident was not yet clear.
A spokesman for the infrastructure operator Infrabel said lighting hit the line on Sunday. SCNB tweeted late Sunday that a signal in the area had been disabled and repaired. A link with the accident had not been established, L'Avenir reported.