President Obama called Gov. Mark Dayton on Monday morning to express his concern about the attack in St. Cloud over the weekend and to offer assistance.

"He asked me to convey his high regard for the work together by federal, state, and local law enforcement officials," Dayton said. "He also asked me to convey his deep appreciation for the heroism of the police officer who stopped the attacker."

On Saturday night, a man stabbed nine people before being fatally shot by an off-duty police officer at a St. Cloud shopping mall. The violence is being investigated as terrorism, federal authorities said.