May 14 (UPI) — French investigators are trying to determine if a stabbing attack in Paris over the weekend was terror-related, as they look into the background of the perpetrator and his acquaintances.

Police identified the attacker as Khamzat Azimov, a French citizen born in Chechnya. Azimov, 20, was shot to death Saturday by police responding to the attack.

Authorities said Azimov stabbed several people during the attack. One died and four were injured.

The Islamic State claimed him as a “soldier” but didn’t provide corroborating evidence. Police said officers first used a stun gun to try and stop Azimov before he was shot.

The 29-year-old man who died in the attack was not immediately named.

Two of the victims were first reported in grave condition, but French Interior Minister Gérard Collomb later told reporters all the victims are recovering.

Born in Chechnya, a part of Russia, Azimov became a French citizen in 2010, ABC News reported. The man’s parents and a friend are being questioned in Strasbourg, France, where officials said Azimov spent his teenage years.

Prosecutor Francois Molins said investigators are still unsure if the mass stabbing attack is terror-related.

Police said Azimov had no criminal record but was on the “fiche S” registry, which flags people French police believe could pose a threat to national security.