A 16-year-old boy who was arrested after a girl of the same age died having taken an unknown substance at a Devon nightclub has been released on bail.
Police had held the teenager on suspicion of supplying a class A drug, such as ecstasy or LSD, in pill form.
Officers went to the Move in Exeter at about 12.30am on Saturday after the girl fell ill, Devon and Cornwall Police said.
She was taken to the Royal Devon and Exeter Hospital and medical staff later said she had died.
Her next-of-kin have been told of her death and are being supported, the force said.
The boy, from the Exmouth area, was arrested on Saturday and released on police bail to return on March 2.
A “number of teenagers may have taken the tablets containing unknown substances”, police said.
They urged “anyone who may also have been affected” and any witnesses to get in touch.
Detective Chef Inspector Lee Nattrass said: “We have identified several teenagers already who reported that they had taken drugs but we would urge anyone else who has felt unwell as a result to seek medical help and to contact us.
“We have seen time and time again that these substances can kill and we have another tragic case on our hands.
“Talk To Frank is a website that has vital information for people about many types of drugs and we ask that parents have open and honest conversations with their children about the risks of drugs.
“You don’t know what they contain and you don’t know the reaction you may have – it could be fatal.
“I urge anyone considering taking drugs to think twice and reconsider.”