A man with severe psychiatric problems killed his mother and sister and seriously injured another woman in a knife attack Thursday in a Paris-region town, officials said. La Parisian reported that the suspect, a 30-year-old man shouted “Allahu Akbar, I will kill them all” during the attack.

Police shot and killed the man soon afterward. ISIS, which has a history of opportunistic claims, swiftly claimed responsibility.

French prosecutors weren’t treating the attack in Trappes, west of Paris, as a terrorism case, Interior Minister Gerard Collomb said. He noted the attacker suffered from serious mental health issues although he had also been flagged for glorifying terrorism.

Collomb said that the man killed his mother at her home and stabbed the other women outside. Still wielding the knife, he then ignored police warnings and was shot and killed, the minister said after meeting officers and prosecutors in Trappes.

He described the man as “unstable, rather than someone who was engaged, someone who could respond, for example, to orders and instructions from a terrorist organization, in particular from Daesh.” Daesh is another name for ISIS.

A long-time friend of the attacker named him as Kamel Salhi, 36. The friend, Said Segreg, said Salhi had no obvious problems, didn’t abuse drugs or alcohol and wasn’t fervently religious.

A government official confirmed Salhi’s name and age. The official spoke on condition of anonymity because he wasn’t authorized to discuss such details publicly.

Salhi was divorced and living with his mother, said Adama Traore, another of his acquaintances in Trappes.

The Islamic State group, via its Aamaq news agency, claimed responsibility. The agency said the attack was motivated by calls from the IS leadership to attack civilians in countries at war with the extremist group. Hours earlier, IS leader Abu Bakr al-Baghdadi urged followers to attack enemies everywhere.

The Islamic State group, which has lost most of the territories it once controlled in Iraq and Syria, has been known to make opportunistic claims in the past, even when there was no established link between an attacker and the extremist group.

(AP)