Morrow High School was evacuated Tuesday morning while school officials tried to determine the source of smoke inside the building.

The school on Old Rex Road is undergoing renovations, “and switched from an old heating system to a new system,” Clayton County schools spokesman David Waller told the Atlanta Journal-Constitution.

“There was apparently something in the new duct work that started smoking and the school was evacuated,” Waller said.

Arriving students were diverted to the Elite Scholars Academy next door.

Waller said just before 9 a.m. that the fire marshal had just cleared the building for students to return.

There were no injuries reported, and no damage to the building.

“Students will return to a regular routine within the next few minutes,” Waller said.