POLICE said today they were keeping an "open mind" about whether two double murders near York were linked.

A frail elderly couple were found dead at their home at Strensall, near York.

It is thought that a neighbour found the couple yesterday, and that they had been stabbed.

Only three hours earlier, the bodies of two sisters in their twenties were discovered. They had been killed in what has been described as a "vicious assault" at a flat in Camblesforth, Selby.

Police said today they were looking for a local man, 34-year-old Mark Richard Hobson, in connection with the deaths of the sisters, and have warned people not to approach him.

Deputy Chief Constable Roger Baker said officers investigating the shocking crimes had "open minds" on whether the murders were linked.

In the Strensall case, police cordoned off the red brick detached house in Strensall Road, at the Towthorpe crossroads, after the bodies of the man and woman - both in their 80s - were found.

Neighbours said that James and Joan Britton lived at the address.

Paramedics had been called to the address at about 11.20am, but the couple were dead by the time they arrived.

A uniformed officer stood guard on the house, while other uniformed officers and a scenes of crime officer carried out initial investigations in the grounds yesterday afternoon.

A full search of the property and surrounding area started at 7pm. Officers at the scene said they could make any comment because of the stage the investigation was at.

North Yorkshire Police said that a 20-strong team of officers was investigating the deaths.

The man leading the investigation, Detective Superintendent Barry Honeysett, said today: "Someone has taken the lives of a frail lady and gentleman in their 80s. It is imperative that this person or persons are brought to justice as quickly as possible.

"I want to hear from anyone who saw or heard anything suspicious on or near the junction of Strensall Road and Towthorpe Lane, close to Strensall Barracks, between 8.30am and midday yesterday."

A force spokesman said detectives also wanted to hear from anyone who walked or drove through the junction between those times, and asked anyone with information to phone York CID on 01904 631321.

Raymond Jackson, owner of York Road Motors, said he had spoken to a neighbour whose wife found Mr and Mrs Britton's bodies, one in the kitchen and the other further in the house. He said the couple had been stabbed.

Mr Jacksons, said the pair were virtually housebound.

He said: "They were so poorly they couldn't have done anything to anyone, they just weren't capable. She was a meek and mild kind of lady and she'd just come out of hospital a few weeks back. They were both lovely people, wonderful people."

Mr Jackson, 66, who had previously worked on Mr and Mrs Britton's car, said they had been burgled in the past. He said: "It's a happy community, small and friendly. We're all very upset."

Neighbour Alan Bell said it would take Mr Britton 40 minutes to shuffle 200 yards from his home to the post box. "He was very frail," said Mr Bell. "Whoever did this is sick."

Another neighbour, Steve Richmond, said the village was in shock. "They were just a nice couple," he said. "I think he was poorly and his wife was poorl. Some of the neighbours used to help them out sometimes and do things for them.

"He used to do the Neighbourhood Watch at one time. It's just shocking. Nothing ever seems to happen round here."

Another neighbour, who did not wish to be named, said he believed the bodies were found by another local resident sometime before 11am yesterday.

He said she had told him the couple had died violently and had blood on their heads.

A uniformed officer stood guard on the house, while other uniformed officers and a scenes of crime officer carried out initial investigations in the grounds yesterday afternoon.

A full search of the property and surrounding area started at 7pm. Officers at the scene said they could not make any comment because of the stage the investigation was at.

North Yorkshire Police said that a 20-strong team of officers was investigating the deaths.

Updated: 12:48 Monday, July 19, 2004