The incident ended after the suspected attacker - who was dressed in a private security uniform and made references to Allah - was shot dead by an off-duty police officer, authorities said.
St Cloud police chief Blair Anderson said eight people were taken to St Cloud Hospital with non-life-threatening injuries following the attack first reported at about 8.15pm.
Mr Anderson said an off-duty police officer from another jurisdiction shot and killed the unidentified suspect. He did not say where the off-duty officer serves.
The suspect made at least one reference to Allah during the attack and asked at least one person whether they were Muslim, the police chief said.
Mr Anderson declined to call the attacks an act of terrorism, saying the motive for the incident was not known yet.
“We will be diligent and get to the bottom of this,” Mr Anderson said, adding St Cloud Police had prior contact with the suspect, but only related to traffic stops.
The mall remained on lockdown following the incident but authorities expected those remaining inside to be released early 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, Minnesota, who were in St Cloud to watch their son play in a college golf tournament, were in the mall when the incident occurred.
“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.”
There also were reports of some shots fired during the attack.
The couple were unharmed and said they helped another woman who was running from the scene to her car.
St Cloud is about 70 miles north-west of Minneapolis.