Five teenage boys remained in an Australian hospital on Thursday, a day after suffering drug overdoses at a private school.
Police said some of the students, aged 14 and 15, were critically ill.
The Gold Coast University Hospital declined to say how many, but said in a statement “they are all steadily improving”.
Seven boys were taken from St Stephen’s College in Upper Coomera early Wednesday afternoon after staff noticed they were drug-affected and deteriorating.
Two were discharged within 24 hours, the hospital said in a statement.
Detective Senior Sergeant Greg Aubort, of Queensland State Police, said the boys had consumed a powdered drug, but gave few other details about its identity.
“It’s not your classical illicit drug,” he told reporters.
Police were investigating how the group obtained the drug, how much they had taken, and whether others might have more of the substance.
“We will follow through in terms of how much was ingested and obviously the barrier here is some of those kids are not able to speak right now,” said Mr Aubort.
“No illicit drug is safe. It’s dangerous and this is a classic example of how wrong it can go when children are pushing the boundaries,” he added.
The affected students had taken various quantities of the drug over several hours on Wednesday morning before the effects became obvious, he said.
School principal Jamie Dorrington spent Wednesday evening at the hospital with the students and their families.
“Our primary concern at the moment is to ensure their well-being, which I’m confident is being looked after,” he said.