A North Texas high school was on high alert Wednesday after a young man threatened a shooting at the school on a social media app.

Police said they arrested a juvenile after who threatened a shooting at Princeton High School on the social media app Burnbook.

"[The suspect] did not list times or individuals, just that it was supposed to be today," Princeton Police Department Chief James Waters said.

The suspect also posted a "selfie," making it easy for investigators to identify him, according to police.

Authorities said they booked the suspect into the Collin County Jail and charged him with making a terroristic threat. They did not release any details about him, but they did confirm that he is not a student at any Princeton ISD school.

"Any threat that concerns a school shooting is a serious threat," Waters said.

Police said they brought in portable metal detectors and performed mandatory bag searches as a precaution. Nine officers patrolled the school Wednesday, up from the usual number of two that are in charge of the entire district.

"We wanted to make sure parents and students felt extra secure while they’re at school," Waters said.

Nearly 1,000 students passed through security on the way to school Wednesday morning.

"I’m sure some of our parents made the decision to keep their children at home today and we respect their decision to do so," district Superintendent Philip Anthony said.

Stay tuned to NBC 5 for the latest developments.