Islamic State has claimed responsibility for an attack in a Minnesota shopping centre in which eight people were stabbed.
The IS-linked news agency, Amaq, released a statement insisting the attacker, who was wearing a security guard's uniform, was a "soldier of the Islamic State".
Speaking shortly after Saturday evening's attack at the Crossroads Center in St Cloud, police chief Blair Anderson said the attacker had "made some references to Allah".
He added: "We have confirmed that he asked at least one person if they were Muslim before he assaulted them."
The FBI say they are investigating the incident as a "potential act of terrorism".
The suspect was shot dead by an off-duty officer from another police force and his identity has not yet been officially released.
Mr Anderson said police are still investigating what happened, adding: "Whether that was a terrorist attack or not, I'm not willing to say that right now because we just don't know.
"We will be diligent and get to the bottom of this.
"Starting tomorrow, things won't be the same here."
He said the suspect, who was armed with a knife and wearing a private security firm uniform, was known to police in St Cloud but only through minor driving offences.
They have "no reason to believe" anyone else was involved in the attacks, which took place in several parts of the shopping centre, including corridors, businesses and common areas.
Harley and Tama Exsted, of Isle, Minnesota, had been in the shopping centre during the attack and Harley told the St Cloud Times: "All of a sudden I heard pop, pop, pop.
"I thought someone tipped over a shelf.
"All of a sudden these people started running - I just saw everybody running our way."
Sydney Weires, who had been shopping with two of her friends, told the St Cloud Times they had heard a loud scream before a security guard sprinted down the hallway, yelling: "Call the cops! Call the cops!".
She said: "We saw these two guys - one was bleeding from the side of his face."
The second man had blood on the back of his shirt, she said.
McKenzie Laubach tweeted: "Currently in hiding in the crossroads mall, hold your loved ones close tonight."
The eight victims were taken to hospital and one was admitted.
Their injuries are not thought to be life-threatening.