Two teenagers were rushed to hospital after consuming a mixture of alcohol and what is believed to be ketamine.
The pair, aged 14 and 15, were taken to Alder Hey Children's Hospital after becoming "seriously ill" last week. An investigation has been launched by North Wales Police into the supply of "dangerous and illegal" substances in the Flintshire area.
The two incidents are believed to be unrelated. North Wales Police has called the supply of drugs to teenagers as "appalling" and branded the matter "extremely concerning".