Four people have been found dead at a house in Peterlee, County Durham. The bodies of a man and three females were discovered after what police suspect was a firearms incident. Officers were called to the house in Greenside Avenue, where a shotgun was found next to the man\'s body, at about 23:45 GMT on Sunday. A Durham Police spokesman said the four dead people were related or known to each other and they were not looking for anyone else. A fifth person, a woman believed to be related to one of the victims, is being treated for shotgun injuries at North Tees Hospital in Stockton. Forensic investigation Firearms officers were called to 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. It is understood the man was in his 40s and while the ages of the females is not clear, the youngest is thought to have been in her teens. The woman in hospital was found at another house in Greenside Avenue. Her injuries are not thought to be life-threatening. An incident room has been set up at police headquarters in Durham. Witnesses or anyone with information about the shootings are asked to contact Durham Police or Crimestoppers.