ROCHESTER, Minn. – Minnesota’s Rochester Public Schools pulled dozens of students from class on Wednesday and will not let them return until they’re properly vaccinated, or show proof of an exemption.

About 80 students were removed from class and hauled to the principal’s office, where school staff attempted to contact their families Wednesday to provide proof they’ve received required vaccinations or an exemption from the state, the Minneapolis Star-Tribune reports.

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A total of 204 students received notices last week that they would not be allowed to continue classes without the necessary documentation, though many had received their shots but simply not provided proof to the school district, RPS spokeswoman Heather Nessler told the news site.

Nessler said the letter was one of several reminders that students must comply with the state’s immunization law, which also allows for exemptions for medical reasons or if the vaccines violate their “conscientiously held beliefs.”

“We’ll just keep working to make sure that either they visit Public Health or one of the clinics in town to fill out the proper forms,” Nessler said.

Superintendent Michael Munoz told the Post Bulletin board members decided last week to bar students without vaccines or exemptions from school buildings because of the “unusually high” number of students who failed to turn in the documentation this year.

“We’ve been working extremely hard to reach out to families … to try to help them,” Munoz said. “But we finally got to the point where we had to draw a line and say, you need to get this done by this date.”

Nessler said about 125 students brought in their vaccination paperwork after the notice went out last week, but officials will not let the remaining 80 students return to class until they’ve complied, as well.

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The students with the missing paperwork come from all age groups and schools “throughout the city,” she said.

“We do not ask our families about why they have or have not vaccinated their children, therefore, we cannot speculate as to why the students haven’t turned in the paperwork,” Nessler said. “We want these students in our classrooms, so we continue to attempt to reach the families and explain the process.”

In the letter to parents last week, RPS officials wrote it’s unclear how they’re expected to enforce the mandatory vaccinations in state law, and noted that an attorney general’s opinion states students “students must be afforded some level of due process” before they’re barred from school.

“Preventing a student from enrolling in school is a serious issue,” the letter read. “The district wanted to make sure it gave families ample opportunity to bring themselves into compliance before it prevented any students from attending school.”

Munoz told the Post Bulletin district officials are now discussing how to provide immunizations to families before the start of school.