The French government has said multiple telecommunications lines have been hit by acts of vandalism.
The damage has affected fibre lines as well as fixed and mobile phone lines as cities around France are hosting events for the 2024 Paris Olympics.
The scale of the impact is unclear, as is whether it has affected any Olympic activities.
The vandalism came after arson attacks hit train networks around France on Friday, hours before the Olympic opening ceremony.
Marina Ferrari, secretary of state in charge of digital affairs, posted on X that damage in several regions overnight from Sunday to Monday affected telecommunications operators.
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She said that led to localised impact on access to fibre lines and fixed and mobile telephone lines.
Telecom providers said they are investigating the damage and effects.
A French police official said at least six of France’s administrative departments were affected, which include the region around the Mediterranean city of Marseille, hosting Olympic football and sailing competitions.
Telecom operators Bouygues and Free confirmed their services were affected.
French media reports said lines operated by provider SFR also were hit.
The parent company of Free said its teams are mobilised to restore services.