Police shot and killed the driver, who drove at high speed for over 100 meters (yards) along the famed Promenade des Anglais seafront before hitting the mass of spectators.
Police shot and killed the driver, who drove at high speed for over 100 meters (yards) along the famed Promenade des Anglais seafront before hitting the mass of spectators, regional sub-prefect Sebastien Humbert told France Info radio.
Broadcaster i-Tele quoted the prosecutor's office as saying the preliminary death toll was 60. Local lawmaker Eric Ciotti told France Info radio more probably had died. Other officials put the number of wounded at at least 100 and possibly more.
Humbert described it as a clear criminal attack, although the driver was not yet identified. Residents of the Mediterranean city close to the Italian border were advised to stay indoors. There was no sign of any other attack.
Almost exactly eight months ago Islamic State militants killed 130 people in Paris on Nov. 13, the bloodiest in a number of attacks in France and Belgium in the past two years. On Sunday, France had breathed a sigh of relief as the month-long Euro 2016 soccer tournament ended without a feared attack.
Officials were cautious about accounts from bystanders that the lone man driving the truck had also opened fire and, amid chatter on social media of a hostage situation, police called on people not to propagate rumors that were hampering their work.