Authorities have now detained seven people over the killings, claimed by Daesh (ISIL), according to Reuters.
The 31 year-old Tunisian killer, Mohamed Lahouaiej Bouhlel, drove at the crowd in the Riviera city on Thursday night, zig-zagging along the seafront Promenade des Anglais for two kilometers as a fireworks display marking the French national day ended, until police eventually shot him dead.
French authorities have yet to produce evidence that he had turned to terrorism. Nevertheless, Interior Minister Bernard Cazeneuve said Bouhlel may have undergone a rapid change.