Isis has claimed responsibility for the shooting attack in Paris that has left one police officer dead and two seriously injured.
In a statement from its Amaq news agency, the extremist group gave a pseudonym for the shooter indicating he was Belgian.
The claim of responsibility came unusually swiftly for the group, which has been losing territory in Iraq and Syria.
The French interior ministry said it was too early to tell what the motive was for the attack in the Champs-Elysees but President Francois Hollande said he was convinced it was a terrorist attack.