JACKSONVILLE, Fla. – A 13-year-old student was arrested after he was found with a loaded semi-automatic handgun in his backpack at Chaffee Trail Elementary School Wednesday, the Jacksonville Sheriff's Office said.

The gun was found in possession of the student, who News4Jax has chosen not to name, during a search for a stolen backpack, police said.

According to the arrest report obtained Friday, the gun, which had six rounds in it, had not been reported stolen.

There have been nine guns, including one starter pistol, found at Duval County schools since the school year began, according to district officials.

A letter was sent home with Chaffee Trail Elementary School students Wednesday about the incident.

In the copy of the letter a parent forwarded to News4Jax, Principal Casie Doyle wrote that no students or staff were injured in the incident.

"The gun was confiscated and the student was taken into custody by law enforcement," Doyle wrote. "The student may face serious criminal charges and will be disciplined according to the Student Code of Contact, which may include expulsion."

Doyle said she appreciated the quick action of her staff and cooperation of students and law enforcement.

"Please talk with your child about this incident, and continue to emphasize their role in keeping our school safe," Doyle wrote in the letter to parents and guardians. "We encourage you to monitor your child's belongings and the items he or she may bring to school."

According to Duval County Public Schools, parents also received an automated call from Doyle.

The mother of a 10-year-old who attends Chaffee Trail Elementary was among the parents who received the call. She told News4Jax that she was alarmed to learned that a gun had been brought to an elementary school, especially.

"I have a fourth-grader here, but all of my kids have actually attended this school throughout -- five kids total. So it's just very scary," she said. "It makes me feel not safe. You send your kids to school to be safe, but now it's, like, you have to almost watch over them daily, pray over them daily."

The mother, who wished to remain anonymous, said she's very concerned by the incidents, which is why she plans to continue to have family talks with her 10-year-old son and his siblings.

"I want them to know how to react and how to respond to things like that because it's not just happening at our school, it's happening at every public place that we go to, and you just don't know when it's going to happen," she said. "So I want to know that they can respond to keep themselves safe and keep others safe if they are around other people."

Superintendent Dr. Nikolai Vitti sent the following statement to News4Jax Wednesday night about the recent spike in weapons found in schools:

"As I always indicate, one weapon brought to school is too many. Today, several were identified in schools throughout Jacksonville regardless of zip code. Thankfully, we have no evidence to indicate that students planned to use them at the school. This has been the case with each weapon discovered at schools over the years. To stop these incidents from reoccurring, we need active parent and guardian involvement. Weapons are arriving to our schools from homes and neighborhoods. We will continue to conduct random searches, which we have expanded, and will continue to actively investigate tips and student behavior. However, parents and guardians must check children’s belongings from backpacks to vehicles before school. More importantly, they must monitor their children’s friends and peer groups, including social media activity and activities outside of the home. Bringing a weapon to school is completely unacceptable. We have, and will, continue to apply expulsion and criminal charges to any student who brings a weapon to school. As a society, though, we must also begin to hold our parents and guardians accountable to the expectation that their involvement and supervision is critical to protecting the safety of their children and also those of the greater society, including school personnel and other children. We encourage students to continue to own the safe school environment they demand by informing personnel of the presence of weapons. In turn, as a team of educators, we will continue to forge relationships with students, parents, and the community to prevent incidents like these from occurring.”