A man who wounded eight people in a knife attack at a mall in Minnesota before being shot dead by an off-duty police officer was a "soldier of the Islamic State," the militant group says.
The man, who was wearing a private security uniform, made references to Allah and asked at least one person if they were Muslim before he assaulted them at the Crossroads Center mall in St Cloud, city police chief William Blair Anderson told reporters on Saturday.
A spokesperson for the US National Security Council said it was aware of the IS claim, voiced via its affiliated Amaq news agency, but deferred to local investigators.
"Whether that was a terrorist attack or not, I'm not willing to say that right now because we just don't know," Anderson said at a news conference.
"We'll figure out what this is and when we do we will be transparent about it," he added. He gave no details of the identities of the victims.
The knife attack, about 100 km northwest of Minneapolis, comes at a time of heightened concern in the United States about violence in public places.
An explosion rocked New York City's bustling Chelsea district on Saturday, injuring 29 people in what authorities described as a deliberate, criminal act. But both New York Governor Andrew Cuomo and New York City Mayor Bill de Blasio said there was no indication it was linked to international terrorism.
In St. Cloud, the attacker entered the mall in the evening as it was busy with shoppers, Anderson said.
He attacked victims at several sites in the centre, which will remain closed on Sunday as police investigate.
The eight wounded were transported to St. Cloud Hospital but none were believed to have life-threatening injuries.
One victim was expected to remain but the other seven had already been released or were expected to be shortly, officials said.
The off-duty police officer who shot the suspect was from an outside jurisdiction.