Waves up to 10 metres high overturn cars and damage restaurants in Côte d'Azur a week before film festival

France's Côte d'Azur was struggling today to retain its seasonal spirit after huge waves and strong winds left the coastline badly damaged a week before the world's rich and famous are due to arrive for the 63rd Cannes film festival.

Waves between four and 10 metres high crashed into the Promenade des Anglais in Nice and the Croisette in Cannes yesterday afternoon, overturning cars and battering seafront restaurants.

As teams of workers laboured through the night to sweep away the displaced sand, clean the pavements and clear the detritus, the deputy mayor of Cannes, David Lisnard, said the cost of the damage would run into millions of euros.

But, he insisted, the freak weather would not be allowed to disrupt the film festival, which is due to open next Wednesday. "There will be a few days of putting things right but everything will be ready, clean, impeccable and sunny," he said.

Others, however, were less optimistic. "The damage was considerable, so the festival will not proceed exactly as forecast," Christophe Marx, an official from the Alpes-Maritimes department, told French radio, without elaborating.

Jean-Luc Passion, who runs a beach on the Croisette, said local businesses would need back-up from the authorities .

"[The festival] is important for the beaches, important for the town and important for the festival, so we will pull out all the stops to get it done. But I think everyone is going to have to help us," he told French radio.

Calling the storms a catastrophe, he said: "We are lost for words. [The waves] came very quickly. It was calm and then suddenly it started and we didn't have time to prepare."

Locals agreed that the waves were the biggest seen on the Côte d'Azur for years, if not decades, and unusual at this time of year. "You have to go back to winter 1985 for waves this size," said Christian Estrosi, the rightwing mayor of Nice and the French industry minister.

René Colomban, president of the Promenade des Anglais beach attendants' union, said he had not seen anything like it since 1959.

Snow falling at the castle in Carcassone
In order to speed the compensation process, the mayors of both resort towns have asked for them to be classified officially as zones of natural catastrophe. Around 15 beachside restaurants were badly damaged.

As reports of damage also came in from Menton, near the border with Italy, and Saint-Raphaël and Cavalaire, officials expressed relief that there had been no casualties. Only one person in the town of Eze was known to have been hurt, while emergency services said they had had to rescue several people from the sea, including an 11-year-old Australian girl on her own n a boat.

While May normally brings the onset of the fine summer months in the south of France, this year it has seen winds of up to 75mph hit parts of country near the Pyrenees and disrupt flights out of Montpellier. Yesterday, to the amazement of the south-western town's residents, snow fell in Carcassonne.