At least 20 people have been injured after a train carrying around 180 passengers derailed in Normandy, France, prompting a major emergency response.

The train was travelling between Rouen and Caen when it came off the tracks near Cléon and Tourville-la-Rivière at around 7.45pm on Friday.

Around 140 firefighters were reportedly deployed to the scene as authorities activated a large-scale casualty response.

French Transport Minister Philippe Tabarot said the initial assessment indicated around 20 people had been injured.

Major disruption across Normandy rail network

Residents have been asked to stay away from the area while emergency crews continue working at the scene.

Rail operator SNCF reported significant disruption on services between Rouen and Caen, as well as between Caen and Le Havre.

Power to the affected railway line was cut to allow firefighters and other emergency personnel to operate safely.

Footage shared on social media showed helicopters above the scene as the emergency operation continued.

The extent of the injuries has not yet been fully established.

Investigation launched

The cause of the derailment remains unknown.

Police and SNCF have launched an investigation to establish how the train came off the tracks.

Passengers are facing significant disruption while the railway remains affected by the emergency response.