The leash has been shortened for unruly city kids.

Suspensions between July and December of 2017 shot up by 20 percent over the same period in 2016, the Department of Education revealed Friday.

There were 14,389 suspensions during that stretch in 2017 compared to 12,000 in 2016, according to the DOE.

While Mayor Bill de Blasio has touted a steep dip in arrests and suspensions under his watch, recent numbers have been less encouraging on both fronts.

School crime — including weapons recoveries, assaults and sex crimes — all increased markedly in the fourth quarter of 2017 when compared to the same period in 2016. The quarter saw the steepest rates of weapons incidents and sex crimes out of any quarter over the past two years.

Year to date, suspensions are up in 2018 by 5.4 percent over the same period last year, according to the DOE.

“This remains a top priority, and we are expanding school-based supports and resources while remaining vigilant in addressing the root causes of conflict,” said deputy schools chancellor Elizabeth Rose regarding the suspension surge.