Two girls needed hospital treatment after taking a parent's prescription drugs at school.
A total of seven first and second-year pupils at Musselburgh Grammar in East Lothian fell unwell at the school on Wednesday after taking the pills the previous day. The girls were sent home from school but staff contacted medical services when they discovered why they were unwell.
Two of the girls required treatment at Edinburgh's Sick Kids Hospital but were later released.
East Lothian Council said the medication had been taken from one of the girls' homes.
A council spokeswoman said on Thursday: "Earlier in the week, an S1 pupil took from home several items of prescription medication and over-the counter medication used by her parents. These were distributed to five other S1 pupils and one S2 pupil, and ingested by all seven pupils.
"Yesterday, several pupils began to feel unwell and two were sent home after parents had been contacted to collect them. Once the school discovered why several were unwell, an ambulance was called.
"The school was advised by the paramedics to get all the girls to hospital as a precautionary measure. Parents of the children involved were contacted so that they could attend the hospital."
Lothian and Borders Police are investigating the incident.
A force spokesman said: "Lothian and Borders Police is investigating after a number of female pupils at Musselburgh Grammar School complained of feeling unwell. It is understood a number were taken to hospital as a precaution after taking some form of tablet. However, they are all now at home recovering.
"Lothian and Borders Police will be working with its partner agencies tomorrow to determine if there was any criminality involved in which case a report would be submitted to the Children's Reporter in due course."
