The man killed one person and injured four on Saturday night
Knife-wielding Paris assailant was 'of Chechen origin'
The assailant in a deadly knife attack in central Paris was born in Chechnya in 1997, a judicial source said on Sunday.
He killed one person and injured four on Saturday night. Two of the victims remain in a serious condition.
The man, who was shot dead by police, had French nationality but was born in the Russian republic. He had been on police radar for radicalism, and his parents have been detained for questioning, French authorities said on Sunday.
ISIS claimed responsibility for the attack in a post via its Amaq news agency, but provided no proof for its claim.
French President Emmanuel Macron tweeted that the country has "once again paid in blood, but will not give an inch to the enemies of freedom".
Mr Macron also praised officers for "neutralising the terrorist".
The attack took place near the city's main opera house in an area full of bars, restaurants and theatres, which were brimming on a weekend night. People were moved from some buildings in the Right Bank neighbourhood.
Witnesses described to French media how they saw the assailant running towards police officers who then shot him.
"We were told to get into a bar quickly. I was curious and went outside again. Outside, I saw a person on the ground about 200 metres from me. The police, fire brigade and ambulance arrived," one woman told LCI television. "I could not see anything else after that."
French interior minister Gerard Collomb called it an "odious" attack. He also hailed in a tweet the "reaction of the police who neutralised the attacker".
"I was taking orders and I saw a young woman trying to get into the restaurant in panic," Jonathan, a waiter at a Korean restaurant, told Agence France-Presse. The woman was bleeding and the attacker then appeared behind her. He said a young man tried to fend off the assailant who fled.
"The attacker entered a shopping street, I saw him with a knife in his hand," he said. "He looked crazy."
Milan, 19, said he saw "several people in distress" including a woman with wounds to her neck and leg.
The French interior minister is holding a special security meeting on Sunday. A series of attacks have claimed the lives of more than 245 people in France in the past three years.