The perpetrator of a knife attack in the Austrian city of Villach was radicalized online and had links to the so-called "Islamic State" group, Austria's interior minister said.

The Syrian suspect, who randomly started attacking passersby with a knife on Saturday, was an "Islamist attacker," Interior Minister Gerhard Karner said on Sunday. The attack left a teenager killed and caused five other injuries.

"It is an Islamist attack with IS connections," Karner told reporters, adding that the suspect was radicalized online "in a short space of time."

What else do we know about the attack?

Interior Minister Karner said Sunday he felt "anger about an Islamist attacker who indiscriminately stabbed innocent people here in this city."

The suspect used a folding knife to target passersby, police said. He was arrested shortly after the attack, when another Syrian — a food delivery driver — stopped him by ramming him with his car.

State governor Peter Kaiser thanked a 42-year-old Syrian man.

"This shows how closely terrorist evil but also human good can be united in one and the same nationality," he said.

The suspect is an asylum seeker but has a valid residence permit and no criminal record, police said.

Rare attack restarts migration debate

Austria's President Alexander Van der Bellen condemned the attack as "horrific."

"No words can undo the suffering, the horror, the fear. My thoughts are with the family of the deceased victim and the injured," he said on X.