MISSOURI CITY, Texas -- Someone fired a BB gun at a middle school student in the school's bathroom, KPRC Local 2 reported Tuesday.

It happened at Lake Olympia Middle School, located at 3100 Lake Olympia Parkway, in the Fort Bend Independent School District on Monday.

The boy told officials that he was leaving the bathroom when he heard a pop and felt something hit his back.

When he went to the school clinic, the nurse noticed that his T-shirt was torn and he had a bruise on his back. School officials believe a BB struck him.

The boy was taken to the hospital as a precaution and was released. The student returned to school the next day.

The boy said he did not recognize the four boys who were inside the bathroom with him.

Police used K-9 officers to search for anything suspicious. A BB was found inside the bathroom, but the gun was never located.

District officials said if they find the person responsible, he will be punished.

"It will be a suspension to the Alternative Education Center. It's a very serious offense. There's no tolerance for any kind of gun at school or use of gun at a school," said Mary Ann Simpson, with Fort Bend ISD.

A letter was sent home to parents Tuesday.

Anyone with information is asked to call Fort Bend ISD Crime Stoppers at (281) 491-TIPS.