A TEENAGE girl died and another was fighting for her life after they were found unconscious at a house today, police said.

Detectives are investigating the possibility that 13-year-old Melissa Strickson may have taken tablets.

A 14-year-old girl, who has not been named, may also have taken tablets and was in a critical condition in hospital, police said.

Two other girls, both aged 11, were also found at the house by officers but did not require hospital treatment.

Chief Inspector Neil Smith said all four girls had been reported missing from their homes in Darwen, near Blackburn, Lancashire, on Monday.

They were seen in early hours of today and traced to an address in Sudell Road where all four were found at 10am.

Melissa, of Tithebarn Street, Darwen, and the 14-year-old girl were taken to Blackburn Royal Infirmary.

Melissa was pronounced dead and the other girl transferred to the intensive care unit at the Royal Manchester Children's Hospital.

Mr Smith said: "We are investigating the circumstances surrounding this sudden death and at this stage we are treating it as suspicious.

"Our main line of inquiry surrounds the possibility that these teenagers may have taken some tablets."

Police said the two occupiers of the house - a man and a woman both aged in their 30s - were being interviewed.

Officers were trying to establish why the girls were at the house and said that the man and the woman were not under arrest.

The couple are not believed to be related to the four teenagers.

The two 11-year-old girls were also being questioned in a bid to discover what substances the children had taken.

Police were understood to be working on the theory that medicinal rather than recreational drugs were involved.