A student was detained after bringing a small-caliber handgun to the Ninth Grade School in Georgetown on Thursday morning, police said.
The gun was not assembled and was not loaded, authorities said.
Capt. Robert Swanigan of the Georgetown Police Department said students notified school officials that they had seen a ninth-grader with a gun on the school bus Thursday morning. School personnel conducted a search and found the disassembled weapon, he said.
School officials sent a letter home to parents notifying them about the incident.
Swanigan said Thursday afternoon that the boy was detained and that charges were anticipated.
It was the second such incident at a Central Kentucky school in less than a week.
A freshman at Lexington's Bryan Station High School was arrested Sept. 7 after school officials found a handgun in his backpack. The student said he found the gun while walking near the school.