A PASSER by who tried to stop a violent robbery taking place in Oxford is being asked to come forward by police.

At 12.30am on Sunday, a 30-year-old man was walking along Woodstock Road when, at the junction of Church Walk, a group of men, who were white and in their twenties, assaulted him from behind.

He was grabbed and punched in the face several times and later needed treatment at the John Radcliffe Hospital.

The gang stole his mobile phone and £30 in cash, but while the robbery was in progress they were disturbed by a member of the public who shouted at them to leave the man alone. They ran off in the direction of Winchester Road.

Det Con Joanne Martin, of Oxford Police Robbery Team, said: "This attack could have been much worse if this person had not intervened and we thank him for that.

"But it is vital he or she now comes forward and speaks to us as that could hold the key to us finding these violent robbers."

Anyone with information is urged to contact Det Con Martin on 08458 505505 or Crimestoppers anonymously on 0800 555 111.