The prosecutor in Paris said on Thursday night that the gunman who killed one police officer and wounded two others at the Champs Elysees has been identified, but said his name would not be revealed until investigators determine whether he had accomplices.
"The identity of the attacker is known and has been checked. I will not give it because investigations with raids are ongoing," Francois Molins told reporters, according to Reuters.
"The investigators want to be sure whether he had or did not have accomplices," he added.
Molins did not comment on the claim of responsibility for the shooting by the Islamic State (ISIS) jihadist group.
The ISIS-affiliated Amaq news agency, in claiming the shooting, also named the terrorist as Abu Yousif, the Belgian.
France has been rocked by a wave of deadly jihadist attacks which began on January 2015 and have killed more than 230 people. The country remains on high alert.
Just this week, French security services arrested two men accused of plotting an attack.
Last month, French authorities arrested four members of a family as part of a preliminary investigation in connection with a plot to carry out an attack