"So far we have no evidence to suggest that they are connected," said police chief of St. Cloud, Minnesota, Blair Anderson, CNN.
Anderson confirmed that the attacker in the commercial center of the city had asked their victims if they were Muslims before stabbing them, but insisted that his motivation was not clear until now.
"If it was a terrorist attack or not, I would not say that so far we do not know," he said.
However, the jihadist group claimed responsibility for Sunday's attack Minnesota.
This attack was perpetrated by "a soldier of the Islamic State", said Sunday the Amaq agency propaganda organ of the jihadist group.
Injured in explosion left the hospital
The 29 people who were injured in a bomb blast Saturday in New York were discharged Sunday while investigators were trying to determine the motives for the attack.
"The 29 injured were discharged and left the hospital. It's very good news," said fire commander of the city, Daniel Nigro, in a press conference.
The mayor of New York, Bill de Blasio, said on his part that even the motive for the attack is unknown.