Investigators probe suspected sabotage of French fiber optic network

Fibre cable outages occurred early Wednesday 27 April, hitting several operators. Authorities suggested the damage to the cables was intentional. © linfokwezi

The Paris prosecutor’s office opened a preliminary investigation Wednesday into the suspected sabotage of fiber optic cables, which disrupted the internet in several regions around France, and said the country's domestic intelligence agency would help with the probe.


The disruptions occurred early Wednesday, hitting several — but not all — internet operators. Authorities suggested the damage to the cables was intentional.

The prosecutor's office opened a preliminary investigation on charges of “damaging goods of a nature of harming the fundamental interests of the nation,” as well as “obstruction of an automatic data processing system” and criminal association, the Paris prosecutor’s office said.

In what appeared to be an unusual move, France's internal intelligence service, known as the DGSI, was helping in the investigation, along with the judicial police.

The cable cuts apparently had no effect on vital services like hospitals. Some customers woke up without internet service and technicians scrambled to patch up the damage.

According to the newspaper Le Monde, the cable cuts hit some customers in Paris’ Ile-de-France region, Alsace in the east, Grenoble in the southeast and the northern Nord region.

'Multiple malicious acts'

On Wednesday, a spokesperson for Free, the worst-affected internet and mobile phone service provider, said that the attacks "took place overnight at 4:00 am. Our teams have been at work since this morning."

In a message on Twitter, the company referred to "multiple malicious acts" targeting its cables which led to outages and slow connections for many clients.

Competitor SFR said it had experienced "several fibre cuts" in the Paris region and in Lyon in southeast France.

Other operators such as Bouygues Telecom and market leader Orange were not affected because they use different networks, but problems were reported by users around the country including in regional cities such as Strasbourg, Reims and Grenoble.

"Cuts to cables have been confirmed in the Paris region affecting fixed and mobile services," Digital Affairs Minister Cedric O wrote on Twitter.

Coordinated attacks

The source of the problem is unknown at this stage, but experts stressed that apparently coordinated attacks on fibre optic cables were unprecedented.

"This sort of incident at this scale never happens," one security source told  French news agency AFP on condition of anonymity. "It's the first time and we don't know who it is for the moment."

The affected operators said their technicians had been working overnight to restore services, with Free saying the problems were "contained".

Other IT companies such as cloud computing groups were also hit by the outages, which forced Free and SFR to move their data on to alternative routes.

"It's a bit like the motorways being blocked and you need to redirect all the traffic on to other roads," said Sami Slim from the data centre company Telehouse.

"It can result in small outages, but the internet works," he said.

The cuts targeted so-called "backbone" cables which carry huge quantities of data between different regions and typically run along motorways or rail tracks.

The Paris-Lyon and Paris-Strasbourg links were apparently targeted.

Deep sea fibre

In March, the French army ministry and the director of the mobile network Orange France warned that a Russian threat to France’s internet connection is ‘credible,’ adding that France’s reliance on international servers makes it particularly vulnerable to a cyberattack or hostile cutting of deep sea fibre optic cables.

in an interview with FranceInfo, Jean-Luc Vuillemin, international network director at Orange, said that France is connected to the web by 51 underwater cables, the largest of which are called “megacables”.

Russian vessels technically have the capacity to cut these cables, and the country has been “interested” in these connections for years, according to Vuillemin. 

This week's cable cuts concerned only land-based connections, and it is not clear whether there are any known suspects. 

In March 2020, fibre optic cables used for Orange's network were intentionally cut in the Paris region, depriving tens of thousands of users of internet connections.

(With wires)