A 14-year-old boy is in critical condition in hospital after taking a red and white capsule.
A 13-year-old boy also had to receive medical treatment by his local doctor in Dundee this week.
It is understood both boys may have consumed a substance which was contained within a red and white capsule and/or possibly other substances.
Detective Inspector Tom Leonard said : “Our thoughts are very much with this young boy’s family and friends. He is currently in hospital where he is gravely ill and in a critical condition.
“It might be that others may have taken the substance and I am urging members of the public, especially parents and guardians to be vigilant as drugs have devastating impact.
“The message is clear, there is no safe way to take drugs – there is always a risk. The effects can be unpredictable and can cause serious harm.
“We are committed to tackling the issues of drugs in our community and we continue to work with partner agencies including local authorities, health officials and medical staff.”