An attempt to sabotage a south-west line connecting Paris with Frances second city of Lyon was foiled.
For now, there has been no official government comment on suspected culprits.
A Russian operation is a reasonable hypothesis, criminology professor Alain Bauer told newspaper lOpinion.
Passengers gather around the departure boards at the Gare Montparnasse train station following overnight arson attacks.Getty Images
The SNCF suggested 800,000 people could be affected overall.
