Updated

A French prosecutor says two judges will investigate allegations that French authorities and the southern city of Nice failed to implement proper security measures before a man drove a truck into crowds of Bastille Day revelers.

Nice prosecutor Jean-Michel Pretre said Wednesday the move follows a complaint by the family of a child who was one of the 86 people killed in the July 14 attack on a waterfront promenade.

In January, Pretre had said preliminary investigations didn't establish "any criminal responsibility" for the event security and dismissed the case.

It is now up to the investigating judges to resume the inquiry and to say whether state or city services or officials should be criminally charged.

Police killed the truck driver, Mohamed Lahouiaej Bouhlel. The Islamic State group claimed responsibility.