PARIS — French authorities are investigating whether sabotage caused a train derailment that injured 44 people in Normandy, after a piece of rail was found on the track, police told The Associated Press on Saturday.

The regional train was carrying 186 passengers from Rouen to Caen when it derailed Friday evening at Cléon, in the Seine-Maritime department of northwestern France.

An 18-year-old woman was among the injured and was evacuated by helicopter to Rouen University Hospital, police said.

A spokeswoman for the French national police communications service, known as SICOP, said that the piece of rail found on the track was “probably” linked to the derailment. She spoke on condition of anonymity because she wasn’t authorized to be publicly named in line with police policy.

Investigators were working to establish whether the circumstances were accidental or involved sabotage, the service said. The prosecutor’s office remained cautious about drawing conclusions, according to the police.

France’s previous rail disasters include the July 2013 derailment at Brétigny-sur-Orge, south of Paris, which killed seven people.

In November 2015, a high-speed TGV train carrying out tests derailed at Eckwersheim, near Strasbourg, killing 11.

More recently, a crash involving two high-speed trains at Adamuz in southern Spain killed 46 people and injured more than 100 in January, according to the Andalusian regional government.