Students as young as five years old have been taken to hospital with minor symptoms after a gas leak at a primary school in Queensland's south-west.

Paramedics were called to the incident at St George State School, about 500 kilometres inland from Brisbane, shortly before 9:30am on Tuesday following reports of a suspected gas leak on site.

Authorities said the source of the leak was traced to gas cylinders near the school office, which were quickly isolated by council staff and firefighters.

Queensland Ambulance Service (QAS) senior operations supervisor John Nolan said 32 people were assessed.

"We assessed 27 paediatric patients ranging from five years old to 14 years old, and five adult patients," Mr Nolan said.

"Of those patients assessed, 14 paediatric patients and two adults were transported to St George Hospital."

Two medics and four nurses sent to assist

Mr Nolan said the patients suffered minor symptoms including abdomen pain, nausea, headaches and mild respiratory symptoms.

Additional medical staff from the local hospital along with QAS crews from Surat and Roma were called to assist at the scene.

Queensland Education said the school acted quickly to evacuate students and staff after the gas leak was detected at the Administration building.

"Classes resumed as normal as soon as the all-clear was given."

The Department said support was available at the school for any students or staff who may require it.