AN “ultra-left anarchist gang” has claimed responsibility for a blackout that plunged 160,000 homes into darkness on the Côte d’Azur – just hours before the Cannes Film Festival awards show.

French prosecutors in Grasse and Draguignan have now launched a probe into suspected sabotage after a shadowy statement was posted online by the group.

In the anonymous release the group said: “We sabotaged the main electrical substation supplying the Cannes metropolitan area and cut down the 225 kV line coming from Nice.”

They claimed the dramatic blackout was a deliberate attempt to cripple key infrastructure including research centres, start-ups, an aerospace factory, the local airport, and military and technological hubs.

Thousands of homes in the iconic French Riviera were left in darkness from around 10am on Saturday until the blackout was resolved at 4.30pm local time.

The suspected saboteurs wrote they targeted the region “on the eve of the Cannes Film Festival awards ceremony and gala evening” in what appeared to be a political statement, BFM TV reports.

Authorities have yet to verify the authenticity of the claims.

An initial arson attack struck an electrical substation in Tanneron, in the Var region, at around 2.45am on Saturday, weakening the power grid.

Hours later, a high-voltage pylon in Villeneuve-Loubet was discovered sawed through – further destabilising the network and triggering widespread outages.