Four teenagers have received hospital treatment after taking tablets from a rogue batch of drugs.
The youngsters, aged 14 and 19, were admitted to hospital after taking the drug which has been described as Valium, but is much stronger.
They suffered from blue lips, lethargy, drowsiness and chest pains, but have all since returned home.
These tablets have been offered for sale in the Brookfield area of Preston and throughout Fulwood. They are popular with young people as they are cheap to buy, but they are potentially lethal as they are far stronger than Valium tablets.
Detective Inspector Warren Atkinson said: “The main concern is that these tablets are being sold illicitly as Valium as opposed to what they really are which is Phenazepam. This is very worrying as these tablets are far stronger than Valium and the effects last much longer.
“So far, four young people have needed hospital treatment as a result of taking this drug and we do not want there to be any more casualties.
“The advice is for anyone who has purchased similar tablets to seek immediate medical attention if they notice any different symptoms or start to feel unwell.”
Three teenagers from Preston aged 15, 16 and 19 have been arrested on suspicion of being concerned in the supply of Class C drugs.
The 15 and 19 year olds have been released on bail pending further enquiries while the 15 year old is currently in police custody.
Anybody with any information can contact police on 101 or Crimestoppers anonymously on 0800 555 111 or on-line at Crimestoppers-uk.org.