NEW YORK (CBSNewYork) — A teenager is in serious condition after police say he was stabbed by a fellow classmate when a dispute over a social media post turned violent at a high school in the Bronx Wednesday afternoon.

Investigators say a 13-year-old girl and 14-year-old boy initially got into a dispute over the weekend over a SnapChat post. The argument carried over into Hostos-Lincoln Academy of Science on Wednesday, when the boy spat in the girl’s face sparking a physical altercation around 1:30 p.m.

The 13-year-old eventually stabbed the 14-year-old in the shoulder with a box cutter, sending him to NYC Health+Hospitals/Lincoln in serious but stable condition.

The girl was taken into custody with charges pending.

Department of Education officials say they’re adding more security measures to the school in response to the violence.