A knife-wielding man was shot dead by an off-duty police officer in a Minnesota mall after he assaulted eight people late Saturday, authorities said.
The attacker made references to Allah and asked a least one person inside the shopping centre in the city of St Cloud if they were Muslim before stabbing them, Police Chief Blair Anderson said.
He said he could not call the crime a terrorist act until the assailant's motive became clear.
The rampage at the Crossroads mall in St Cloud, about 100 kilometres north-west of Minneapolis, began shortly after 8 pm Saturday (0100 GMT Sunday).
The assailant, who was wearing a uniform that resembled that of a private security officer, stabbed people at multiple locations before an off-duty police officer shot and killed an him, Anderson said.
Eight people were taken to hospital with non-life-threatening injuries.
Police had dealt with the individual on three earlier occasions but all for minor offenses, he said.