GRINNELL, Iowa — A 13-year-old Grinnell Middle School student was arrested for allegedly making violent threats to students and staff on Monday.

At around 8:34 a.m. officers with the Grinnell Police Department responded to an unknown problem involving a 13-year-old student at the middle school.

School officials informed police of a complaint from a concerned parent about several school emails their child received. Those emails came from another student and appeared to be threatening and disturbing in nature, police said.

Police discovered that the student who wrote the emails had been using his school Gmail account to send messages to other students using a numbered code to hide certain words. Police said they also found handwritten notes and drawings that suggested acts and threats of violence towards students, staff, and property.

The 13-year-old has been charged with Threat of Terrorism and has been released to their parents. The police said the 13-year-old and their parents are cooperating fully with the ongoing investigation.