MURDER squad detectives are urgently seeking a vital witness to a vicious assault on a Bradford street, which has left the victim fighting for life.

The 40-year-old man was walking home when he was attacked in Hollybank Road, Great Horton, shortly after midnight on Monday.

He suffered severe head injuries and was last night in a critical but stable condition, in a medically-induced coma, at Leeds General Infirmary.

A 21-year-old man and a 16-year-old boy, who were arrested on suspicion of assault, have been released on bail pending further inquiries.

Police investigating the assault are keen to trace a man who is believed to have witnessed it.

The man, who is white and either bald or with very short hair, was seen walking towards Hollingwood Lane at the time of the attack and would have probably seen or heard what happened.

Detective Chief Inspector Steve Snow, of Protective Services Crime, said yesterday: "We believe there was a man who walked past this incident as it was occurring, but he probably won't know what has happened as a result.

"A man is now seriously ill in hospital as a result of the attack and we are urgently appealing for this witness to come forward and tell us what he might have seen or heard."

Det Chief Insp Snow issued reassurance to the public.

He said: "This was an isolated incident, which is not immediately connected to the community where it happened."

Det Chief Insp Snow said the victim lived in Great Horton and was married with children, who was on his way home when he was attacked.

He added: "He remains in a critical but stable condition at Leeds General Infirmary."

He said that no weapons had been used in the assault.

Police had been called to the scene, in Hollybank Road, at 12.13 am on Monday. A section of the street, outside a house which was unconnected with the incident, was initially cordoned off and under police guard, as Crime Scene Investigation officers examined the area.

Anyone with information is asked to contact police on 101, or Crimestoppers, anonymously, on 0800 555 111.