French police were investigating a possible arson attack as being the main cause for a power outage which hit the Alpes-Maritimes region in southern France on Saturday, including Cannes which is hosting its world-famous annual film festival.

"We are looking into the likelihood of a fire being started deliberately," said a spokesperson for the French national gendarmerie, adding that no arrests had been made at this stage.

The local authority for the Alpes-Maritimes region had said earlier on Saturday that the western part of the area, which includes Cannes, was suffering from a major electricity outage and that RTE France was working on restoring power.

The Cannes Film Festival said the closing ceremony would take place as planned on Saturday evening.

"The Palais des Festivals has switched to an independent power supply, allowing all scheduled events and screenings, including the Closing Ceremony, to proceed as planned and under normal conditions," it said in a statement.