People stand near the entrance on the north side of Crossroads Centre in St Cloud, Minnesota. Photo / AP
The man in the security guard uniform strode into the Minnesota mall just after 8pm local time somewhere near Sears.
He flashed a knife "big enough to hurt someone," police said, and asked his would-be victim a question: Are you Muslim?
In the ensuing minutes, police say, nine people were stabbed in the attack yesterday at the Crossroads Centre. Their attacker was ultimately shot and killed by an off-duty police officer.
Authorities in St Cloud called the assaults a "potential terrorist attack," citing the incomplete investigation at the sprawling crime scene. They say the assailant, who has not been identified, made reference to Allah and asked at least one victim if he was Muslim.
Isis (Islamic State) took credit today through the Isis-linked Amaq Telegram Agency:

The attacks shattered a sedate evening at Crossroads Centre, the largest mall in Minnesota outside Minneapolis and St Paul."The executor of the stabbing attacks in Minnesota yesterday was a soldier of the Islamic State and carried out the operation in response to calls to target the citizens of countries belonging to the crusader coalition."
Danny Carranza was watching his children at the play area when the attack started, he told the Saint Cloud Times.
"People came running around the corner, and I freaked out because I thought it was a terrorist attack or something because I saw a lot of people, so I grabbed my kids," he told the newspaper.
"I ran as much as I could and I heard someone yell 'Stop! Stop!' As soon as the door shut I heard gunshots."
Sydney Weires, Maggie Gelke and Jenna Remmele, students at the College of Saint Benedict and Saint John's University, were bored and decided to go to the mall. Weires needed some things from Target, and they didn't have other plans, so they made a 16km drive.
The women stopped in J.C. Penney and were headed to the Target, when they decided to make a quick stop into Victoria's Secret.
About 8.10 pm, they left the lingerie store and continued onto Target. Then they heard screaming and saw two men "just dripping with blood," Weires told theWashington Post.
"One guy had blood dripping down his face," she said. "The other guy it looked like he had just been stabbed in the back and his whole back of his shirt, it was grey but it was covered in blood."
I ran as much as I could and I heard someone yell 'Stop! Stop!' As soon as the door shut I heard gunshots.
Danny Carranza
The men were staggering, Gelke said, but they were yelling - "there's a guy running around the mall with a knife".
"The only thing that they said that we heard clearly," she said, "was get the f*** out of the mall."
The three women were already moving. They sprinted past Victoria's Secret and through J.C. Penney to the parking lot.
"We started to drive home and we passed a bunch of cop cars going past us at 90 miles an hour (145km/h)," Gelke said.
At the centre, off-duty officer Jason Falconer - who works part time in nearby Avon, Minnesota - was squaring off against the suspect, authorities said.
Falconer "was there at the right time and the right place," St Cloud Mayor Dave Kleis said.
Falconer is a gun instructor and a former police chief in Albany, Minnesota. He owns Tactical Advantage, a gun store and range that also offers classes for people to qualify for Minnesota's conceal and carry permit.
One of the classes Tactical Advantage offers deals with the use of deadly force against armed subjects, according to its website. The classes help students "hone their skills and (makes) them ready for the real world".

Kleis said that final altercation between Falconer and the stabbing suspect was captured on a surveillance camera.
Falconer "identified himself as a police officer and you actually see (the suspect) going down by command then immediately lunging toward the officer," Kleis recounted.
"The officer then fired a few rounds," Kleis said. "You see (the suspect) fall, you see him get back up, three times. Even after (the suspect was fatally shot) he was still attempting to get back up."
After the suspect was killed, investigators emphasised that it would take time to fully understand his motivations and determine any terrorism links.
Even after the investigation, Chief Blair Anderson told reporters at a midnight press conference, the fear that the attack instilled in Minnesotans would be difficult to shake.
"It has hit home for us," Anderson said. "It's an awful day. Starting tomorrow, things won't be the same."