Five schoolchildren have fallen ill after ingesting an “unknown substance” at a school hostel.
Two pupils are in hospital after the incident at the Papdale Halls of Residence in Kirkwall, Orkney, on Wednesday.
Police are leading a joint investigation working with NHS Orkney and Orkney Islands Council.
The local authority issued a warning to parents and carers urging them to ask their children about “a clear capsule that may contain a brown or other coloured liquid”.
A council spokesperson said: “It is important that anyone with such a capsule, hands it over to their parents, the school, an appropriate adult or the police and not to ingest it.”
Medical staff have said the conditions of the two children in hospital are “not causing concern at this time”.
Orkney Islands Council said it would be working with the police, NHS Orkney and the Orkney Drugs Dog charity to educate and engage with students throughout the region’s schools about the dangers of substance misuse.
A spokesperson said: “We are asking for parental support to assist in dealing with this situation and want to stress that this is not about punishment, this is about the health and wellbeing of our young people at this time.
“We would really appreciate any assistance parents and carers can provide.
“Our grateful thanks are extended to the staff at the Papdale Halls of Residence who dealt with the incident swiftly and professionally ensuring the young people concerned received the medical attention and support required.”
The Papdale Halls of Residence provide accommodation for secondary school students from both the North and South Isles to enable them to attend Kirkwall Grammar School.
A Police Scotland spokesperson said: “Police Scotland officers are liaising with NHS Orkney and Orkney Islands Council after five pupils took unwell at the Papdale Halls of Residence in Kirkwall yesterday, Wednesday, January 26, 2022.
“Two young people remain in hospital however medical staff have said their conditions are not causing concern at this time.
“A joint investigation is ongoing to establish the circumstances surrounding the incident and enquiries are ongoing.”