ST. CLOUD, Minn. (AP) — A man in a private security uniform stabbed eight people at a Minnesota shopping mall, reportedly mentioning Allah and asking at least one victim if they were Muslim before an off-duty police officer shot and killed him, authorities said.

All eight victims were treated at a hospital for wounds that weren’t life-threatening, St. Cloud police Chief Blair Anderson said at a news conference. A St. Cloud Hospital spokeswoman, Chris Nelson, said five of the eight were released and three remain hospitalized. No further details of their conditions were released.

The attack happened at around 8 p.m. Saturday at the Crossroads Center in St. Cloud, a city of about 65,000 people 60 miles (95 kilometers) northwest of Minneapolis.

A man in a security uniform and armed with a knife stabbed people in several locations in the mall, including corridors, businesses and common areas, the chief said. He said an off-duty police officer from another jurisdiction shot and killed the suspect, though he didn’t say where that officer serves.

Anderson said the man reportedly made at least one reference to Allah and asked a victim if they were Muslim before attacking them. But he declined to call it an act of terrorism, saying the motive was still unknown.

“We will be diligent and get to the bottom of this,” Anderson said. “Starting tomorrow, things won’t be the same here.”

An Islamic State-run news agency, Rasd, claimed Sunday that the attacker was a “soldier of the Islamic State” who had heeded the group’s calls for attacks in countries that are part of a U.S.-led anti-IS coalition.

It was not immediately clear if the extremist group had planned the attack or even knew about it beforehand. IS has encouraged so-called “lone wolf” attacks. It has also claimed past attacks that are not believed to have been planned by its central leadership.

Anderson didn’t identify the attacker, but he said police had had three previous encounters with him, mostly for minor traffic violations. He said authorities have no reason to believe anyone else was involved in the attack. The FBI is helping with the investigation.

“The entire mall is an active crime scene,” Anderson said.

A police spokesman, Sgt. Tim Burke, declined to say Sunday whether the attacker worked as a security guard at the mall or was just posing as one.

The attack began shortly after an explosion in a crowded New York City neighborhood injured 29 people. A suspicious device was found a few blocks away and safely removed. Hours before that, a pipe bomb exploded in Seaside Park, New Jersey, shortly before thousands of runners were due to participate in a charity 5K race. There was no indication that any of the incidents were linked.

The St. Cloud mall remained on lockdown following the attack, and authorities eventually released those inside. It was closed on Sunday.

Photos and video of the mall taken hours after the incident showed groups of shoppers waiting to be released, including some huddled together near a food court entrance.

Harley and Tama Exsted, of Isle, were in St. Cloud to watch their son play in a college golf tournament and were in the mall when the attack happened.

“All of a sudden I heard pop, pop, pop,” Harley Exsted told the St. Cloud Times. “I thought someone tipped over a shelf. All of a sudden these people started running. I just saw everybody running our way.”

The couple were unharmed and said they helped another woman who was running from the scene to her car.

Adonis Samuels, 42, of St. Cloud, was outside the mall where his wife Roxanne works as a manager at Clinique at Macy’s.

“She called me on the phone and told me she was hiding under the counter with a customer,” Samuels said. She later called and said she was safe in a secured area.

Samuels remained outside, watching for her. He said he’d seen her through the glass doors at one point so he knew she was safe.