The driver was shot dead after barrelling the truck two kilometres through the festive crowd on the palm-lined Promenade des Anglais, sending hundreds fleeing in terror and leaving the area strewn with bodies.
The Nice terror attack is the third major strike against France in less than 18 months and prosecutors said anti-terrorist investigators would handle the probe.
Nice terror attack came eight months after Islamic State attacks on Paris nightspots left 130 people dead, dealing a hard blow to tourism in one of the world's top destinations.
The attacker struck after a day of military pomp and ceremony in Paris where armed forces, tanks and fighter jets swooped down the Champs Elysees avenue and spectacular firework displays.
At least 84 people were killed, 18 were in critical condition and over hundred have been injured after a truck ploughed through the throng of people celebrating Bastille Day in Nice, France. President Francois Hollande called it a “terrorist” attack. The truck driver opened fire even as the truck barreled two kilometers through the festive crowd on the palm-lined Promenade Des Anglais. As panic set in, terrified crowd ran for cover. The police shot dead the driver, identified as a 31-year-old Tunisian, but not before the promenade turned into a graveyard.