Mandarin Middle School implemented enhanced security measures on Monday after a social media threat recently surfaced, the school district says.

Duval County Public Schools says bag checks and metal detectors were used to screen students as they entered the building. 

"We have been made aware of a social media threat regarding Mandarin Middle School, and the district will be implementing enhanced security measures," Duval County Public Schools said in a statement. 

The code yellow was lifted around 1 p.m. without incident. 

According to school officials, Duval County School Police also investigated and determined it was a student at the school who made the threat through a post. 

The post is a level-three infraction of making a school-wide threat, according to the school district. The student is facing an immediate suspension and a referral to a hearing officer to possibly be put into one of the school district's disciplinary alternative schools. The School Police will also review the incident with the State Attorney's Office, the school district says. 

Several parents say the threat kept them from sending their kids to school. Parents say they got an automated call before 7 a.m. Monday from the school's principal informing them about the threat and about the extra security measures. Some say while they're happy the school took precautions, walking through a metal detector into school shouldn't be normal.

This is the message parents received from Principal Moses Williams: 

"Good afternoon Mandarin Middle School families. This is Principal Williams calling with an update to our security situation at the school today.

I have mixed feelings as I report that our school police department has identified the student responsible for the recent social media threat. While I am thankful that our police have succeeded in this matter and that there is no threat to our school, I am disappointed when any student faces such significant disciplinary consequences.

The threat received constitutes a level three infraction of making a school-wide threat. This comes with an immediate suspension and referral to a hearing officer for possible placement out of Mandarin and into one of the district’s disciplinary alternative schools.

Because of the student’s age, our school police will also be in conversation with the state attorney’s office to determine if any further course of action is warranted.

I know that you will be relieved to know the matter has been concluded, and our code yellow has been lifted.

I do hope that you will use this situation to have a very important conversation with your child.

Any kind of threat to a Duval County Public School will be taken seriously. A threat is never a joke and will have significant consequences.

Again, thanks to the individuals that shared the post. By communicating and working together, we will always do everything we can to keep our school community safe. Thanks for your partnership in this and have a great rest of the day."

Additional police staff were also present throughout the day. 

"Anytime we are aware of a threat, we will take it seriously and we are thankful for the individual who reported this to the police," the district said.

First Coast News spoke to Superintendent Dr. Diana Greene in November after staff at A. Philip Randolph High School found a gun in a student's backpack. Because of that, students there now have to walk through metal detectors every day. 

According to Greene, all high schools in the county have metal detectors and randomly screen students, but A. Philip is the first to require screenings for every student. First Coast News asked the school district if there are any plans to implement metal detectors at the middle schools and haven't heard back yet. 

Click here to visit the Duval County Public Schools website.