Prosecutor's office spokeswoman Agnes Thibault-Lecuivre said some of the 84 French and foreign nationals who lost their lives after last Thursday's massacre died subsequently in the hospital.
Authorities have not released an official list naming the dead from the July 14 Bastille Day rampage in the southern French city.
In a speech to army reserves today, French President Francois Hollande said 15 people wounded in the Nice attack are still in the hospital "between life and death." He praised the French emergency and security services' work during and after the attack in which Mohamed Lahouaiyej Bouhlel, a troubled 31-year-old Tunisian, drove a truck down a seaside boulevard full of people who had watched a fireworks show.