Police were last night searching for an injured man who left a lengthy trail of blood along the Thames towpath in Oxford.

Police cordoned off a long stretch of the towpath after being alerted to a pool of blood of a bench near Iffley Lock at 8am yesterday.

They discovered a trail of blood along the towpath and then found a blood-stained bicycle at the Tandem pub in Kennington, more than a mile away.

Detectives contacted paramedics to check on what incidents there had been in the area and it emerged an ambulance had been called to the area to help a man with a hand injury, which was believed to be self-inflicted.

He ran off and refused treatment when paramedics tried to help him and yesterday police were trying to find him.

They appealed for the wounded man or anyone who knew him to come forward so that he could be helped.

One witness said she saw two men one of whom had a hand injury at Iffley Lock at about 11.30pm on Sunday.

Det Sgt Russell Simpson, of Oxford CID, said: "I would like to reassure the public that the scene at the towpath or the blood stains are not linked to any serious crime. We believe the injuries are self-inflicted.

"We are obviously concerned for the welfare of this man, and I need to urge him and anyone who may be with him to first, seek medical attention and second, to contact police to let us know that he is OK. I would also like to hear from anyone who may have seen the man in the area."

The towpath was cordoned off until lunchtime yesterday.

A man who cycled along the towpath to the Tandem pub in the morning said: "A police officer asked me to walk my bike as close to the river as possible. He obviously wanted the area undisturbed."

He said the towpath was cordoned all the way between Iffley Lock and Kennington.

Ambulance spokesman Helen Robinson said: "Just after 1am, we treated the person concerned but he absconded before we were able to complete a more thorough assessment."

Anyone with information can contact police on 08458 505505 or Crimestoppers on 0800 555111.