With the government vigilant over the risk of more such attacks during the Games, French authorities on Sunday arrested an activist from an ultra-left movement at a site belonging to national rail operator SNCF.
Police said the cables of several telecoms operators had been sabotaged in six areas of France overnight from Sunday into Monday but Paris was not affected.
AFP confirmed with major carriers including Free and SFR that they had been affected, although no major disruptions had yet been reported.
“It’s vandalism,” said Nicolas Chatin, spokesman for SFR, one of France’s four biggest operators.
“Large sections of cables were cut. You would have to use an axe or a grinder.”
But the group minimised the impact of any disruption, saying that in the end only 10,000 fixed line customers had been affected.
Paris chief prosecutor Laure Beccuau said police had opened a second criminal probe into the fibre optic cable incidents, saying the perpetrators were suspected of “causing material damage with the intention of harming fundamental interests of the nation”.
The ultra-left activist was detained at Oissel in northern France on Sunday and had access keys to SNCF technical premises, tools and literature linked to the “ultra-left”, said a police source, asking not to be named.
He was placed in police custody for questioning in Rouen, the main city of France’s Normandy region.
But there was no immediate link between him and the investigation into the attacks early Friday, the source said.
Unknown individuals had in the early hours of Friday attacked three different railway installations in different parts of France, causing days of chaos on the high-speed network as Paris hosts the 2024 Olympic Games.
Interior Minister Gerald Darmanin told France 2 television that the authorities were looking into the theory that “ultra-left” movements were behind the attacks.
French services have “identified a certain number of profiles that could have committed” the sabotage acts, he said.
He said the “attacks were very intentional and well targeted”.
Darmanin added that this was “the traditional mode of operation of the ultra-left”.
“The question is whether they were manipulated by other people or is it for their own account,” he added. “We are progressing well and we will find them.”
He said the saboteurs clearly had “information” about the installations but declined to comment when asked if he believed they had come from within the SNCF.
An email purporting to claim the attacks was received at the weekend by several French media outlets, using rhetoric typical of militant groups and slamming the Olympics as a “celebration of nationalism”.
But it contained no detail as to how the attacks were carried out and police sources who spoke to AFP cautioned against seeing the email as a claim of responsibility.
