More than 200,000 households were temporarily left without electricity in southern France after power cuts, which threatened to disrupt the Cannes Film Festival.
Around 160,000 households in the Alpes-Maritimes area lost power from around 10am on Saturday, officials said.
Supplies were restored to all homes at around 3pm local time, on Saturday, hours before the festival’s closing ceremony – which was unaffected.
Arson is suspected after the outage, which followed an overnight fire at an electrical substation near the city, leading to a high-voltage power line falling.
Laurent Hottiaux, the prefect for the area, pointed to “serious acts of damage to electrical infrastructures”.
He promised to use all means available to “identify, track down, arrest and bring to justice the perpetrators”.
A prefect is a high-ranking government official who represents the state in a French region.
Authorities’ suspicions were apparently confirmed on Sunday, when anarchists claimed responsibility for the outage in an anonymous statement reported by local outlet BFM, quoting public prosecutors in Grasse and Draguignan.
In the statement posted by two anarchist groups, they said: “On the eve of the Cannes Film Festival awards ceremony and gala evening, we sabotaged the main electrical substation supplying the Cannes metropolitan area and cut down the 225 kV line coming from Nice.”
Events early on Saturday were affected, Cannes Film Festival organisers said, but the Palais des Festivals – the Croisette’s main venue – coped by switching to an independent power supply.
Organisers said in a statement: “All scheduled events and screenings, including the closing ceremony, will proceed as planned and under normal conditions.”
Train services were disrupted, along with some traffic lights, leading to jams and confusion, while screenings at the Cineum, one of the festival’s satellite venues, were briefly suspended, organisers said.
Some 45,000 homes were temporarily without electricity in nearby Nice and the neighbouring towns of Saint-Laurent-du-Var and Cagnes-sur-Mer, energy supplier Enedis said, after the weekend’s second power outage overnight on Saturday.
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Power was restored on Sunday morning, but the city’s mayor, Christian Estrosi, put it down to “malicious acts”.
Mr Estrosi said power was “restored very quickly”, at 6am, Franceinfo said on its website.
He ordered all sensitive electrical infrastructure in the city to be placed under police protection.
Nice’s deputy mayor, Gaël Nofri, said “according to information provided by the firefighters, an access door to the transformer was forced”.
The city’s airport and tram network were affected.
