One dead in Paris knife attack claimed by IS
Investigators on Sunday were probing the background of the 20-year-old Frenchman who carried out the stabbing spree, for which the Islamic State group claimed responsibility.
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.
Interior Minister Gerard Collomb hailed in a tweet the "sang-froid and reaction of the police who neutralised the attacker".
Police identified the assailant as Khamzat A., who grew up with his family in Strasbourg, eastern France, a source close to the inquiry told AFP. The city is home to a large community of refugees from the Muslim Russian republic of Chechnya.
He became a French citizen in 2010 after his mother was naturalised, government spokesman Benjamin Griveaux told French television.
Although Khamzat had no criminal record, he had been on both of France's main watchlists for suspected radicals - the so-called "S file" as well as a more targeted File for the Prevention of Terrorist Radicalisation (FSPRT), which focuses on people judged to be terror threats - since 2016.
One source said he had been questioned by anti-terror investigators last year "because he knew a man who was in contact with a person who had gone to Syria".
Hundreds of Chechens have joined Islamic militant groups in the Middle East, North Africa and elsewhere in recent years.
The Islamic State group said one of its "soldiers" had carried out the Paris attack, according to the SITE monitoring organisation, but provided no evidence to back their claim.
Panic broke out on the busy Rue Monsigny with people fleeing into bars and restaurants as the man walked along stabbing people, yelling "Allahu akbar" ("God is greatest") before police shot him dead.
"I was on the cafe terrace, I heard three, four shots, it happened very fast," said 47-year-old Gloria.
"Then the bartenders told us to come inside very quickly. Then I went out to see what was going on, and then I saw a man on the ground," she added.
The attack comes as France is under a constant threat from terrorism. A string of jihadist attacks have claimed the lives of more than 245 people around France in the past three years.
French President Emmanuel Macron tweeted: "France has once again paid the price in blood but will not give an inch to the enemies of freedom."