French authorities believe arson may have played a role in a power outage Saturday in southeast France that threatened to jeopardize the Cannes Film Festival's closing celebrations, including the much-anticipated Palme d'Or ceremony.

Power was restored hours before the ceremony, around 3 p.m. local time, as music began blasting again from beachfront speakers. The end of the blackout was greeted with loud cheers from locals.

Authorities were investigating the likelihood of arson in a fire at an electrical substation near Cannes that weakened the grid overnight, a spokesperson for the French national gendarmerie said.

The power outage happened hours later, after a high-voltage line fell at another location. Authorities were investigating what caused that line to collapse.

About 160,000 households in the Alpes-Maritimes area lost electricity.

In a statement, Laurent Hottiaux, the prefect for the area, condemned "serious acts of damage to electrical infrastructures."

"All resources are mobilized to identify, track down, arrest and bring to justice the perpetrators of these acts," said Hottiaux.

Cannes Film Festival organizers confirmed the outage affected the early activities of Saturday and said the Palais des Festivals — the Croisette's main venue — had switched to an independent power supply.

The lineup was unveiled last month for Cannes.

"All scheduled events and screenings, including the Closing Ceremony, will proceed as planned and under normal conditions," the statement said. "At this stage, the cause of the outage has not yet been identified. Restoration efforts are underway."

Traffic lights in parts of Cannes and the surrounding city of Antibes stopped working after 10 a.m. local time, leading to traffic jams and confusion in city centers. Most shops along the Croisette remained closed, and local food kiosks were only accepting cash. Train service in Cannes was also disrupted.

Screenings at the Cineum, one of the festival's satellite venues, were briefly suspended, the festival added.

The Palme d'Or was later awarded Saturday night, with Jafar Panahi's revenge thriller "It Was Just an Accident" taking home the festival's most prestigious prize.