Winthrop Grade School students and staff evacuated to the nearby high school Monday morning after a smoky HVAC appliance set off fire alarms in the school’s gymnasium.

Students evacuated the building around 10:30 a.m., Superintendent Becky Foley said, and returned to their classrooms by 1:30 p.m. The 400 students were initially moved outside and then to the all-purpose room at the nearby Winthrop Town Office before being relocated around 11 a.m. to the cafeteria at Winthrop High School, where they ate lunch.

The evacuation prompted the delay of after-school pre-K buses but was not expected to impact other students’ afternoon transportation, Foley said.

No injuries or damage was reported, beyond the faulty air handler that prompted the evacuation. Winthrop fire Chief Dan Brooks could not immediately be reached for comment.

Foley, who was inside Winthrop Grade School when fire alarms sounded, said she smelled smoke during the evacuation. She said fire alarms continued to sound for at least a half-hour while fire crews searched for the source of the smoke.