A man and a woman aged 20 and 18 died at the festival yesterday

A major music festival in southern England has been cancelled after an 18-year-old woman and 20-year-old man died on Saturday.

The two-day Mutiny Music Festival was entering its fifth year in Cosham, a suburb of Portsmouth.

The woman became unwell just after 7pm on Saturday and was taken to Queen Alexandra Hospital where she later died.

The man was found collapsed around half an hour later and was rushed to the same hospital where he died later that evening.

Acts including Dizzee Rascal, Craig David, Sean Paul and British actor Idris Elba were due to headline over the weekend.

At around 9pm yesterday, the festival shared a Twitter post warning that it was “aware of a dangerous high strength or bad batch substance on site.”

"We strongly urge you to not take any substances whatsoever and to report any symptoms of illness / discomfort immediately to medical, welfare, security or the safeguarding team.

"Please stay alert and look out for each other."

Police officers and dogs are now at the site investigating the circumstances of each death, which are being treated as separate incidents.

Neither is being treated as suspicious.

This morning organisers said they were cancelling the rest of the event as a safety precaution.

Organisers said their “thoughts and prayers are with the family and friends at this very difficult time and we will continue to work with the authorities to support them in any way possible.”

Hampshire police have confirmed they are investigating the deaths and the substance warning issued by the festival.