Two women were killed and a man and a teenage boy were seriously injured in a suspected stabbing on Christmas Day.
Detectives launched a murder investigation after they were called to reports of a stabbing at a block of apartments in Bletchley, Milton Keynes, at 6.36pm on Wednesday.
A 38-year-old woman and a 24-year-old woman both died at the scene. A teenage boy and a man aged in his late twenties were taken to hospital with serious injuries, where they remain in a stable condition.
A dog was also injured and was taken to see a vet, but it did not survive.
A 49-year-old man from Milton Keynes was arrested on suspicion of murder and attempted murder. He remains in police custody.
Forensic teams have been spotted scouring a home near the scene in Santa Cruz Avenue as police confirmed they are not looking for anyone else in connection with the stabbing.
Senior investigating officer Detective Chief Inspector Stuart Brangwin, of Thames Valley Police’s major crime unit, said: “Firstly I would like to extend my deepest condolences to the families of the women who have tragically died in this shocking incident.
“We have launched a double murder investigation, which may be concerning to the wider public; however, we have made an arrest and are not looking for anyone else in connection with this incident and the parties are known to each other.
“Members of the public will see a large police presence in the area while our investigation takes place. If you have any questions or concerns, please feel free to approach our officers and they will do their best to help.
“Anyone with information or footage which you think could help our investigation, please call us on 101, quoting reference number 43240622935.
“Alternatively, you can make a report online, or contact the independent charity Crimestoppers on 0800 555 111.”