A schoolgirl died after taking a rogue ecstasy tablet at a nightclub during a night out with friends.
Regane Lenaghan Maccoll, 17, is thought to have tried a red 'Mortal Kombat' pill before she collapsed at The Arches nightclub in Glasgow on Saturday night. She died shortly afterwards in hospital.
In separate incidents, a 19-year-old woman was admitted to Glasgow Royal Infirmary and three men aged 18, 26 and 27 were taken to Crosshouse hospital in Kilmarnock.
They are all believed to have taken the same type of super-strong Mortal Kombat pills as Regane, which have a dragon on the back.
As police issued a warning about the drugs, NHS Ayrshire and Arran consultant James Stevenson urged clubbers not to touch them.
He said: "People who choose to take drugs are playing Russian roulette with their life.
"They have no way of knowing what they are taking. As a result, some of them will die.
"I would appeal to young people, don't believe what you're being told by someone giving you drugs.
"There's no such thing as a safe, illicit drug. You could be swallowing anything."
Dr Alastair Ireland, of Glasgow Royal Infirmary, said: "We're concerned about people taking this dangerous drug and cannot stress enough the effects they can cause, including death.
"I would urge anyone who has taken one of these tablets and begins to feel unwell to seek immediate medical help."
The Arches is a leading venue on the club scene. A spokesman said they were 'deeply saddened' by Regane's death, adding: "We are working closely with Police Scotland to assist them in any way we can."
Linda, Booth, the head of St Peter the Apostle High School, which Regane attended, described the teenager as 'popular, hard-working and enthusiastic'.
She said: "Our whole school community feels a deep sense of grief and our thoughts and prayers are with Regane's family and friends at this devastating time.
"Regane was a popular, hard-working and enthusiastic pupil and staff always found her to be pleasant and well-mannered.
"This is a real tragedy for a girl who worked so hard and I'm sure would have gone on to achieve so much in her life."
Police Scotland said it was still unclear what caused Regane's death and a post mortem examination will be carried out.