The Minnesota elementary school student was arrested and released later that day.
Police say there is no indication the boy's parents will face any charges.
Police confirmed via Twitter shortly after the incident that a man had been arrested.
Beise says the boy was interviewed by police and released to his parents.
The alert was raised at around 1pm on Monday with the arrest taking place around two hours later. The school has just under 800 students.
Daniel Ricciardo doesn't do boring, reality check for Pierre
Pilot Red bull Daniel Riccardo in bright style became the victor of the third race of the season in Formula 1 . Verstappen's 10-second penalty dropped him behind Hamilton in the classification, however.
Sauk Rapids borders St. Cloud on the northern edge.
School Superintendent Bruce Watkins says the boy lashed out at the other students until an adult intervened. I don't think he had an intended target when he came to school with a knife. Pleasantview has students in grades kindergarten through fifth grade. "We're not sure exactly why he came to school with a knife". There are approximately 790 students enrolled at the elementary school. School officials say they will work with the family of the attacker and law enforcement in dealing with the incident. The incident resulted in three students being injured and the aggressor was contained in the office.
Parents of children attending Pleasantview all received an electronic notice of the incident Monday morning.
The chief says he doesn't know if the boy had been bullied or had mental health issues.
Watkins said the school made mental health counsellors available to students and staff. Classes went on as scheduled. Please know in situations like this the District's discipline policy is applied and aggressive students are not allowed in the building (s).