NEW YORK – Teachers and parents are sounding off about new student discipline rules imposed by Mayor Bill de Blasio that prevents schools from suspending certain students.

“Eliminating the ability of a school to intervene using suspensions, without understanding what drives the suspensions or providing educators with the resources … is unrealistic and shortsighted,” United Federation of Teachers Vice President Richard Mantell said at a public hearing in Manhattan on Monday.

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De Blasio announced new discipline rules for the city’s schools while on vacation in Italy last month. The changes prohibit schools from suspending any student in kindergarten through second grade, and formalizes procedures for adding or removing metal detectors from school entrances, the New York Daily News reports.

City officials already banned suspensions for pre-K students last year.

The city has also banned suspensions for insubordination in all grades, a change that’s driving a trend of less suspensions but more violent crime in schools. The anti-suspension policies follow directives from the Obama administration in recent years to reduce suspensions of minority students, because minority students are suspended at a higher rate than white students.

According to a recent City Journal op-ed, “Schools chancellor Carmen Farina says that current discipline policies disproportionately penalize black and Hispanic youngsters, and give white kids a pass.

“It’s the administration’s latest application of the disparate-impact dodge: any policy that negatively affects a protected class – irrespective of the relevant facts – is by definition racist and thus unacceptable.”

The situation is also playing out in other large urban school districts across the nation with similar results. In many schools working to lower suspensions of minority students by ignoring bad behavior or using “restorative justice” discipline that allows them to design their own punishment, teachers and parents are reporting massive chaos in the classroom.

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Instead of sending misbehaving students home to think about their antics, administrators are forcing teachers to keep them in the classroom, where they’re disrupting lessons for all students.

Ironically, it’s New York City’s United Federation of Teachers union – which helped to elect De Blasio – that’s become the most outspoken opponent to the mayor’s new student discipline edicts.

“Children who are … disrupting classrooms are not going to be helped by this plan to ban suspensions in grades K-2 – and neither will thousands of other children who will lose instruction as a result of those disruptions,” UFT President Michael Mulgrew wrote in an open letter to Farina.

According to The City Journal:

City Hall claims that there has been a 50 percent decline in schoolhouse arrests between 2011 and 2015—from 3,155 to 1,555—implying that fewer arrests are the product of less classroom crime. But fewer arrests don’t necessarily mean less crime.

According to the state education department’s School Violence Index, the number of violent incidents in city schools increased dramatically during de Blasio’s first year in office, from 12,978 in 2013–14 to 15,934 in 2014–15. At the same time, the index itself—the ratio of violent incidents to total school enrollment—jumped by 22 percent, the steepest increase on record. According to the reform group Families for Excellent Schools, “[t]here were more than twice as many ‘assaults with physical injuries’ reported by city schools to the State Education Department [during the 2014–15 school year] than the total number of crimes” publicly acknowledged by the de Blasio administration. Meanwhile, the NYPD reports a 26 percent increase in the number of lethal weapons confiscated by school safety personnel through May 8 of the just-concluded academic year, compared with 2014–15. So it would seem that a dangerous trend continues.

And while de Blasio wants to keep more misbehaving students in class, he’s also making it easier for schools to remove metal detectors. His new policy allows school leaders to request a safety assessment to add or remove the scanners, and the city’s school safety workers union thinks the change will only lead to more violence.

“Unfortunately this is going to lead to more children bringing weapons to schools,” Local 237 President Gregory Floyd told the Daily News last month. “There could be a mass shooting. The mayor is making schools less safe.”