What We Know About the Attacks on France’s Rail Network

Just hours before the opening ceremony of the Paris Olympics, France was rocked by a series of arson attacks on its rail network on Friday, stoking fears over security during the Games.

No one was killed or reported injured, but the damage to France’s high-speed train lines caused major delays as thousands of local and international travelers were expected to converge on Paris for the ceremony and the Games. The arson attacks, which authorities have described as “criminal,” come amid heightened security concerns, when France is the center of a global spectacle.

Here’s what we know about the attacks and the resulting disruptions:

Is this a terrorist attack?

That is not clear yet, but France’s prime minister, Gabriel Attal, has described the fires as “acts of sabotage that were carried out in a prepared and coordinated way.” The police and intelligence services are investigating these “criminal acts,” he added in a post on social media.

So far, evidence shared by the French authorities suggests that the attacks were planned and deliberate. The fires all broke out at the same time on Friday, around 4 a.m. local time, said Patrice Vergriete, France’s transportation minister.

Jean-Pierre Farandou, the head of France’s national rail company, S.N.C.F, described the attacks as “very meticulous work.” The fires were set in pipes that carry cabling necessary for signaling, and located on key bifurcation points on the rail, meant to maximize the damage, Mr. Farandou said.