Six high school students are being treated in hospital after ingesting an "unknown powder" in far north Queensland.
The alarm was raised with emergency services on Wednesday morning that several students at William Ross State School in Townsville were symptomatic after ingesting a mystery substance.
Queensland Ambulance Senior Operations Supervisor Martin Taylor said the students had reportedly ingested a brown powder from a bag.
"It was a powder that was brought in by a member of the school and they had no idea what it was initially," he said.
One student was nauseous and vomiting when paramedics arrived and seven other kids were assessed at the scene.
Six students were taken to Townsville University Hospital in a stable condition.
Mr Taylor said the students were generally well but upset.
"Everything was minor and we were just taking them to hospital for observations," he said.
Mr Taylor said the powder was handed over to police for further toxicology tests.
The Department of Education told AAP it is investigating the incident.
