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 revelers, killing at least 84 . (Reporting by Marine Pennetier; Writing by Bate Felix; Editing by Andrew Heavens)