Image copyright PA Image caption The house is the subject of a detailed forensic operation

Four people have been found dead after a shooting at a house in Horden, near Peterlee, County Durham late on Sunday.

The bodies of a 42-year-old man and three women were discovered at the house in Greenside Avenue. A shotgun was found next to the man's body.

Police said three other people in the house managed to escape. A woman, 19, was treated for minor injuries.

It also emerged the man, named locally as Michael Atherton, was licensed to own six firearms.

Police said they were treating the incident as a murder inquiry and were not looking for anyone else. All four dead people were related to each other.

Firearms officers attended the scene after a caller reported that a number of people had been shot inside a semi-detached house.

The victims' bodies were found in different rooms in the downstairs of the house, and paramedics confirmed all four were dead at the scene.

The area has been cordoned off since shortly after midnight and a forensic investigation is under way.

An incident room has been set up at police headquarters in Durham.

Media playback is unsupported on your device Media caption Assistant Chief Constable Michael Banks gives details of the shootings

Det Supt Paul Goundry, who is leading the investigation, said all the deceased were related and that the Durham force had had "minor contact" with the family in the past. As a result the force has made a voluntary referral to the Independent Police Complaints Commission (IPCC).

He said a 19-year-old woman was among those who managed to flee the house through an upstairs window. She was treated for injuries to her wrist and shoulder and later released from hospital.

Assistant Chief Constable Michael Banks said the dead man was licensed to own six weapons, three of them shotguns and a further three "section-one" firearms.

He said: "I can confirm that a resident at that address was the lawful holder of shotgun and firearms licences and we cannot confirm at this stage whether any of those weapons that were lawfully held have been used in this.

"At this moment in time it is my understanding that the person was licensed for three shotguns and three section-one firearms."

He said section-one firearms were a particular category of firearms which require greater authorisation than a shotgun licence.

Mr Banks said: "This is a tragic event. We have four people who died and our thoughts and feelings are with their family and friends at this moment.

"I would like to reassure our communities that the police are in control of this incident.

"At this moment, we are looking for no-one else in relation to this inquiry."

He said a number of calls were received in the police control room that shots had been fired at Greenside Avenue in Peterlee.

Image copyright PA Image caption Floral tributes have been placed outside the house

He said: "Our information within those numerous messages was that several people had been shot.

"The police were dispatched to the scene and shortly after midnight, as our officers entered the house, it was discovered that a man and three women were dead in the house.

"It is our belief at this stage that they died of gunshot wounds."

He said there were no signs of a disturbance at the house.

Det Supt Goundry said one person initially arrested in connection with the shootings was later released without charge.

He added that all those dead were in their 20s and 40s.

A number of floral tributes were placed outside the semi-detached property.

Labour party ward councillor Paul Stradling said it was the most shocking incident he had come across in 30 years as a politician.

"Greenside Avenue is normally a very quiet area so it has shocked everybody," he said.

"It's a typical North East village, quiet most of the time with a little bit of anti-social behaviour, but crime levels are usually low."