Following the incident, officers launched an investigation and have made seven arrests to date.
A Spokesman for the Police said: “Quite simply, drugs are dangerous. The consequences could be beyond anything you imagine and we are imploring people to say no to drugs and to stay safe.”
Guernsey Police will not be providing further updates at this time.
Anyone with any information is asked to contact Guernsey Police on 725111 or CrimeStoppers anonymously on 0800 555 111.
Pictured top: The 16-year-old is in a critical condition at the Princess Elizabeth Hospital.