Police were called to Hazardville Memorial School in Enfield on Tuesday after a bullet was found inside.
The 22-caliber bullet was found in a hallway just before 3 p.m., according to Supt. Jeffrey Schumann, who sent a recorded phone message to parents on Tuesday afternoon.
Police were called to the school at 68 N. Maple Street and arrived within four minutes, Schumann said.
School staff searched the backpacks of all students and no other bullets were found. No weapons were found or reported as well, Schumann said.
Police will have extra officers at the school on Wednesday.