PARIS - Five people held for questioning over the Bastille day attack in the southern French city of Nice will appear in court on Thursday and could be placed under formal investigation, a judicial source said.

The suspects have already been transferred from the custody of the French anti-terrorism unit SDAT to the Paris court where they could be charged, the source said.

Islamic State has claimed responsibility for the attack by 31 year-old Tunisian driver Mohamed Lahouaiej Bouhlel who rammed his truck into a crowd of Bastille day revellers, killing at least 84 .