NICE • French President Francois Hollande invoked the spirit of national unity yesterday as he led a tribute to the 86 people killed in a terrorist truck attack in Nice on Bastille Day.

Yesterday's ceremony in the Riviera resort city had been postponed until a day after the three-month anniversary because of storms in the region.

"What was attacked on July 14 was national unity," Mr Hollande told hundreds of victims' relatives and officials invited to the ceremony.

"It is the monstrous aim of the terrorists to attack some in order to terrify others, to unleash violence in order to sow division... Well, I tell you, no, this evil enterprise will fail," he said.

In the July 14 attack, a 31-year-old Tunisian extremist rammed a 19-tonne truck into a crowd of 30,000 holiday revellers on the Promenade des Anglais seafront before police shot him dead.

More than 400 people were injured, some grievously.

The Islamic State in Iraq and Syria said the driver, Mohamed Lahouaiej Bouhlel, was one of its followers.

The massacre marked a peak of brutality in a string of terrorist attacks in France over the past two years that have ramped up security fears while stoking anti-immigrant sentiment ahead of presidential elections next year.

Mr Hollande has tried to unite the country behind calls for a "France of fraternity" in the fight against extremism.

But solidarity remains elusive.

A boar's head was found outside a mosque in Nice last Tuesday, the second such anti-Muslim incident this year.

Meanwhile, many families of the Nice attack victims are still struggling to deal with their grief.

Mr Vincent Delhommel Desmarest, who runs a restaurant on the Promenade des Anglais, is still haunted by the bloodbath and has yet to return to work.

"You don't sleep at night. I saw the whole thing - the lorry bearing down, the mutilated, decapitated bodies," said Mr Desmarest, leader of a victims' group.

AGENCE FRANCE-PRESSE