The video shows the man speaking in French pledging allegiance to Abu Bakr Al Baghdadi
ISIS releases video of hooded 'Paris attacker'
ISIS, which claimed the knife attack that killed one person in central Paris on May 12, released a video on Sunday of a man it claims was the attacker.
The ISIS propaganda agency Amaq posted the video online using Telegram, featuring a young man wearing a hood with only his eyes exposed and the lower part of his face covered by a black cloth.
Speaking in French, he vows allegiance to ISIS leader Abu Bakr Al Baghdadi.
The attack in the Right Bank on Saturday night by a knifeman, later shot dead by police, left one person dead and four wounded.
"The author of this knife attack in Paris is a soldier of the Islamic State and the operation had been carried out in retaliation against the states in the coalition," said a "security source" at Amaq, referring to the international forces, including France, that are fighting militants in Syria and Iraq.
The attacker killed at the scene by French police has been identified as Khamzat Azimov, a 20-year-old French citizen born in Chechnya who had been on two watchlists for suspected extremism.
The man attacked five people with a knife, one of whom died, police said. Two remain in a serious condition.
ISIS claimed responsibility for the attack on Saturday in a post via its Amaq News Agency, but provided no proof of its involvement.
Witnesses described to French media how they saw the assailant running towards police officers who 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. In a tweet he hailed the "reaction of the police who neutralised the attacker".
France is under a constant threat from terrorism. A series of attacks have claimed the lives of more than 245 people in the past three years.