The train, carrying 186 passengers between Rouen and Caen, came off the rails at around 7.45pm near the Renault factory in Cléon, south of Rouen.
A police source told reporters on Saturday that investigators had discovered a fragment of rail on the track and were treating the possibility of a deliberate act as the main line of inquiry.
The derailment prompted a major emergency response, with authorities activating a mass-casualty plan. Around 130 firefighters, five medical teams and 80 emergency vehicles were deployed to the scene.
Rouen public prosecutor Sébastien Gallois said 44 people had been injured, including an 18-year-old woman who was evacuated in a critical condition.
Tests carried out on the train driver for alcohol and drugs were negative, he added.
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Passenger describes 'really shocking' derailment
One passenger, 24-year-old Louis, described how the journey suddenly turned violent as the train began shaking.
“Suddenly there were a few jolts, and then after about three seconds it got stronger and stronger,” he told ICI Normandie radio.
“I couldn't stay in my seat any more. The windows partially shattered, the stones from the track came into the carriage. It was really shocking. I'm still shaking.”
Passengers who escaped injury were taken to a room made available by the mayor of Cléon while emergency services dealt with the scene.
A press photographer at the site on Saturday morning saw large numbers of railway workers around the damaged train as investigations and recovery operations continued.
SNCF Réseau, which manages France's rail infrastructure, said traffic on the line was immediately suspended following the derailment, while electricity to the tracks was cut to allow emergency crews to work safely.
The incident caused what SNCF described as “major disruptions” to services between Rouen and Caen, as well as between Caen and Le Havre, in both directions.
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Services resume as investigation continues
SNCF Réseau said some services had resumed by Saturday morning, although disruption remained on the Rouen-Caen route.
The line normally has around 10 return services each weekday and six at weekends. SNCF Voyageurs said replacement buses had been introduced to help passengers continue their journeys while the affected section of railway remained unavailable.
The derailed train itself will remain in place until prosecutors give permission for it to be removed, as investigators continue examining the circumstances surrounding the accident.
The discovery of the piece of rail is expected to form a central part of the investigation as authorities try to establish whether it was deliberately placed on the track and, if so, who was responsible.
No information has yet been released about any suspects or a possible motive.
SNCF said it would provide “full cooperation in complete transparency” with the investigation.
The derailment comes on one of Normandy's principal regional rail corridors, linking Rouen with Caen and providing onward connections towards Le Havre.
While investigators continued their work on Saturday, railway teams were also focused on restoring normal services and assessing any damage to the track and surrounding infrastructure.
Authorities have not yet indicated when the Rouen-Caen line is expected to return to its normal timetable.
(with newswires)



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