POLICE investigating the deaths of four people in two double murders last night released a picture of a man they want to question.

They took the unusual step of naming 34-year-old Mark Richard Hobson - but warned he could pose a danger to the public and should not be approached.

The double murders took place within 25 miles of each other in North Yorkshire. Although detectives are not connecting them directly, they say they are keeping an open mind as to whether they were linked.

The bodies of a frail elderly couple, both in their 80s, were found shortly after 11am on Sunday at their home in Strensall, just north of York.

About three hours earlier, the bodies of two young women, believed to be sisters, were found in the bedroom of a house in Millfield Drive at Camblesforth, near Selby. They had been the victims of a vicious assault.

Mr Hobson lived at the house, in a quiet cul-de-sac, and police said they wanted to speak to him in connection with the women's deaths.

"His present whereabouts are not known and police inquiries have so far failed to locate him," said Detective Superintendent Javad Ali. "We are appealing for him to contact the police as a matter of urgency."

He added: "We believe that Hobson may pose a risk to members of the public and we strongly advise people not to approach him.

"If you believe you have seen him, please contact the police immediately."

Assistant Chief Constable Roger Baker said the possibility of whether the Camblesforth and Strensall killings were linked had been raised.

"All I can say now is that we have open minds on this and that we will continue to review the possibility regularly," he said.

As forensics teams and detectives combed the site of the Camblesforth killings, similar operations were under way at the cordoned-off house of the Strensall couple.

Police are still to name the elderly couple or the circumstances in which they died, but neighbours said the detached house was the home of John and Joan Britton.

Anyone who can help with the Strensall inquiry is asked to contact York CID on (01904) 631321,

At Camblesforth, Mr Hobson was described as white, 5ft 9in tall, slim, with a shaven balding head and a two-inch scar above his left eye.

Anyone who knows his whereabouts is asked to call police on (01904) 669651 or Crimestoppers - 0800 555 111.