Fifteen primary school students have been hospitalised after falling ill from eating lollies on a Queensland school bus.
The incident in Townsville has prompted the local hospital to activate a Code Brown to deal with an "external emergency".
The Queensland Ambulance Service (QAS) was called to Bluewater State School, north of Townsville, just after 10am.
QAS senior operations supervisor David Wright said 22 children had ingested an "unknown substance", which the ABC understands was lollies, and several started displaying minor symptoms.
"The symptoms include some nausea, a little abdominal pain, and light-headedness," Mr Wright said.
Chief executive officer of the Townsville Hospital and Health Service, Kieran Keyes, said 15 students were in hospital as at 4:30pm.
The children are aged between seven and 11 years old.
"All children are in a stable condition," Mr Keyes said.
"Our incident management team is coordinating the response and we are awaiting the arrival of further children impacted by this isolated incident who require our care."
QAS senior operations supervisor David Wright said children who weren't taken to hospital were monitored at school by paramedics.
"A lot of them were saying [they were feeling], in children's words, crook in the tummy, feeling like they're going to vomit and feeling a little dizzy," Mr Wright said.
"All their vital signs, their important numbers, have remained within their normal limits for their age groups.
"For children it can be quite daunting.
"They're all mild symptoms at this moment and they're all doing the best they can."
Investigation underway
Townsville District Duty Officer Senior Sergeant Jonathan Searle said the bus was being examined.
"The circumstances surrounding how the children became unwell is a part of our investigation," he said.
"In my 18 years of service this is the first time I've ever been involved in or heard of an incident of this nature."
Senior Sergeant Searle said the students had started showing symptoms 10 to 15 minutes after arriving at school.
He said police were assisting the Department of Education and Queensland Health.
"It will be a comprehensive investigation … certainly when children are involved we don't want to pre-empt anything," he said.
School staff praised
In a statement, a spokesperson for the Department of Education said Bluewater State School holds the safety of students and staff was its highest priority.
"The [Education Department] is aware of an incident that occurred today at Bluewater State School which required the assistance of emergency services," the statement said.
"School staff acted quickly to attend to the students while the Queensland Ambulance Service and parents were contacted.
"The Queensland Police Service also attended and are investigating.
"Due to privacy issues the department is unable to provide any further information.
"Guidance or counselling services are being made available for anyone who may require support."
