Authorities say a 13-year-old boy is in custody after he pulled out a gun in a New York City public school and threatened another student.

Police say he was one of three teenagers arrested Monday and charged with criminal possession of a weapon. The 13-year-old was additionally charged with menacing.

Investigators say the 13-year-old threatened another student with a gun, which was later found in the jacket of a 15-year-old boy at Public School 169 in Manhattan. Police say a box of ammunition was found in a 14-year-old boy’s jacket.

Department of Education spokeswoman Toya Holness tells WNBC-TV that incident is deeply alarming. She says no students were injured.

Last month, three students were caught with guns on city school campuses in the span of a week.

(AP)