NAUGATUCK, Conn. (AP) An unknown odor has prompted officials at a Connecticut high school to dismiss early and cancel classes.

Crews responded to Naugatuck High School on Thursday afternoon on reports of a noxious odor. They metered the air and found no signs of hazardous gases in the area. The cause of the odor hasn't been determined.

Superintendent Sharon Locke confirmed that students were sent home early ``out of extreme precaution.''

The school will be closed Friday so the fire department can return and check for potentially harmful gases.