No cause for the attack is yet clear, but the mayor of Nice has confirmed that the truck carried weapons and grenades. French media are also reporting that the driver fired shots while running into the crowd, which has not been officially confirmed.

Hollande said that "the terrorist character of the attack cannot be denied." The anti-terrorism prosecutor is still investigating the attack.

The French consulate in Turkey had cancelled its Bastille Day celebrations earlier due to security threats, reported Liberation.Almost eight months ago, Islamic State group militants killed 130 people in Paris. On Sunday, France had breathed a sigh of relief as the month-long Euro 2016 soccer tournament ended without a feared attack.