THE detective leading the investigation into a vicious assault on a man while he slept has made an urgent appeal for people with information to come forward.

Three men and a youth were arrested by Darlington police yesterday in connection with the incident in the town, but the attacker is still thought to be at large.

Detective Inspector Paul Harker is also urging people not to panic, because the evidence does not suggest it was a burglary that got out of hand.

He said: "We are appealing for anyone with information, or any witnesses, to come forward.

"Although we have made four arrests, we are still trying to find the main man behind the attack.

"However, we are also trying to reassure the public, as we do not believe the attack was a result of a burglary or robbery which went wrong.

"People should not be concerned about being attacked in their sleep. This is a very rare and unusual case and the evidence appears to suggest it was a directed attack on the victim."

The 42-year-old victim was still being treated for head injuries in the intensive care unit at the James Cook University Hospital, in Middlesbrough. His condition is critical, but stable.

The attack happened while he slept beside his girlfriend in a first-floor bedroom of her house in Greenbank Road at about 5am on Thursday.

His injuries are thought to have been caused by being hit with a blunt object.

Det Insp Harker said: "As we are not able to interview the victim, we are still trying to piece together the background to this case.

"Not only do we want to hear from people with information about the attack, we also want people to contact us if they think they know the man.

"We believe we have a name for him, but we do not think he is originally from Darlington and may not have been here for very long. At this stage, we do not have contact with his next of kin."

The offender is thought to have had two dogs with him.

They were described as a white Yorkshire terrier with brown spots and a brown Yorkshire terrier cross.

A 14-year-old, two 18-year-olds and a 21-year-old were arrested yesterday in connection with the attack, and were released on bail pending inquiries.

Witnesses are urged to call police on 0845 60 60 365.

Alternatively, people can call Crimestoppers in confidence on 0800 555 111