Mustang High School was placed under a short lockdown Thursday morning after a gun was found on campus, according to a letter to Mustang High School parents.

About 9:30 a.m., an unattended bag was reported at the media center. A short time later, the bag's owner was identified. 

The owner of the bag and the weapon was identified as an employee of the school. He said he planned on going target shooting the night before and forgot to take the gun out of his bag in the morning. 

The employee has a certified handgun license. 

"The district is taking appropriate action for this employee," Mustang High School principal Teresa Wilkerson said in the letter.

No one was injured.