A Minnesota principal who allowed a boy accused of sexually assaulting two classmates to remain in school vowed to punish students if they staged a walkout - and then called cops on a concerned mom who questioned why the boy was allowed to prowl the same hallways as the alleged victims. 

Parents in Zimmerman, a town about 40 miles north of Minneapolis, were left fuming at not only Principal Marco Voce but at the school board after it refused to address the allegations during a meeting on Monday.

A judge overseeing the boy's court proceedings allowed him to continue attending the school, parents said.  

Meantime, students at Zimmerman Middle/High School staged a walkout last Friday to express their dismay and were warned by Voce that they could be suspended for participating and breaking district rules.

Cassie Bonine, whose daughter is a student at the high school, attended Monday night's Independent School District 728's board meeting with hopes of asking questions, but learned none would be answered. 

'We were all denied,' she told DailyMail.com on Thursday. 'None of us were allowed to speak at the meeting.'

Bonine said she later encountered Voce on her way to the restroom.