Police have arrested a 23-year-old man and a 20-year-old woman on suspicion of murder following the deaths of three children in an arson attack.

Firefighters were called to a mid-terraced house in Jackson Street, Worsley, Greater Manchester just before 5am on Monday.

A 14-year-old girl, named locally as Demi Pearson, was declared dead at the scene and an eight-year-old boy and a seven-year-old girl were taken to hospital and later died.

The children's 35-year-old mother, named locally as Michelle Pearson, is in a serious condition in hospital while a fourth sibling, a three-year-old girl, is in a critical condition.

Chief Superintendent Wayne Miller of Greater Manchester Police said: "I want to describe what this incident is, it is the murder using fire of three children and we have a three-year-old girl fighting for her life who is seriously ill. This will devastate this family forever and words cannot describe what they are going through."

Two 16-year-old boys who were also in the house freed themselves before fire crews arrived.

Demi was a pupil at Harrop Fold School in Salford, which featured in the Channel 4 documentary Educating Greater Manchester.

Head teacher Drew Povey said: "We are devastated at the tragic loss of life today in our community. Our thoughts and prayers are with the family involved."

Police had been called to the property three hours before the fire with reports that their bin had been set alight.

Greater Manchester Police confirmed there were "earlier incidents" at the address and said the force has made a self-referral to the Independent Police Complaints Commission.

A large police presence remained at the scene throughout the day and both ends of the street were cordoned off.

Tearful locals stood at the end of the cordons and consoled each other with embraces.

One woman, who did not wish to be named, said she knew the mother of the family, naming her as Michelle Pearson.

She said: "I have known Michelle for years. The family have lived here for a long time. We are all just in shock.

"There has been trouble round here before but it's more wannabe gangsters, teenage stuff."

Chief Superintendent Miller said: "In what is such a heart-breaking set of circumstances, we have been doing our very best to support the family in every way that we can and carry out our inquiries quickly and sensitively.

"This evening, two people are in custody but we are still appealing for people who witnessed the fire itself or the events leading up to it to get in contact with us and tell us what they know."