Stradey School was evacuated today following concerns that there was a fire within the building.
Mid and West Wales Fire Service attended the school to investigate.
A spokesperson for Carmarthenshire County Council said: “The school’s smoke alarms were triggered at 01:30pm and the whole school was evacuated safely.
The Fire and Rescue Service attended and conducted an investigation of the building.
There was no sign of fire, only smoke.
All pupils have left the school for the day safely and there is no damage to the building.”