A 19-year-old man has died after falling ill at Creamfields dance music festival in Cheshire.

Police said the teenager, from Warrington, had been seen looking unwell by security staff at 12.15am on Saturday. He was assessed by a doctor on site before being taken to Warrington district general hospital, where he died.

He is the second teenager to die at festivals in England this weekend, after a 17-year-old girl died of a suspected drug overdose at Leeds festival.

DI Alistair Hinze, of Cheshire police, said there did not appear to be any suspicious circumstances surrounding the man’s death.

“A file will prepared for the coroner and our thoughts are with the family at this incredibly difficult time,” he said. Police said a postmortem examination would take place in due course.

A Creamfields spokeswoman added: “We are deeply saddened to hear of this tragic accident. We send our deepest condolences to his loved ones and we continue to work closely with the authorities.”

Earlier, the festival issued a warning about “extra-strong” ecstasy pills in circulation at the site amid rising alarm over the strength and purity of so-called party drugs.

Organisers of the dance music festival in Daresbury, Cheshire, said extremely potent MDMA tablets were being taken on site, where Calvin Harris and the Chemical Brothers topped the bill on Saturday night.

A Creamfields spokesman said: “There are extra-strong MDMA pills in circulation. If you feel hot, develop a fast heart rate or have a friend who is unresponsive, please seek help with a member of staff as soon as possible.”

Experts have called for increased testing at festivals after research found that many drugs contained other harmful ingredients, such as an MDMA pill that was actually n-ethylpentylone, a long-lasting cathinone that can cause anxiety, paranoia, insomnia and psychosis.