A 16-year-old boy is seriously ill in hospital after being hit by a train as he walked alongside the tracks on a railway viaduct in Bolton.

The train stopped and two off-duty nurses who were passengers got off to help the boy, who had head injuries.

They managed to strap him to a spinal board and brought him back on to the train, which was on Tonge Viaduct and was due to stop at Hall i'th' Wood station.

The train then took him a few hundred yards to Union Road, Tonge Moor, where paramedics were waiting for him.

Safety procedures and concern for his injuries meant that it was about two hours before the boy, from Astley Bridge, was put in an ambulance and taken to the Royal Bolton Hospital.

The incident involved Wednesday's 7.58pm Manchester Victoria to Clitheroe service. It is understood the teenager remained in a hospital high dependency unit last night.

A witness reported via The Bolton News' website that the train driver had stopped and called railway officials for authority to allow the nurses to leave the train to tend to the boy.

"The train driver, poor guy, did a fantastic job. Even in shock, he went to aid the lad," the witness told the website.

"Two nurses got off the train to help him. They put him on the train until they could get him to a point where they could get him into an ambulance."

A British Transport Police spokesman said: "It is believed the 16-year-old, from Astley Bridge, was walking alongside the tracks when he was struck from behind by the train.

"There were access difficulties at the area where he was struck and he was transported on the train to Union Road to the ambulance."

A spokesman for Network Rail said: "We were informed of the accident at 8.30pm and closed the line so the emergency services could reach it.

"Off-duty nurses got off the train and helped the injured boy on to a spinal board and he was transported on the train to the ambulance."

An ambulance spokesman said a paramedic in a rapid response car arrived at 8.36pm, followed by an ambulance, within 10 minutes of the emergency call at 8.31pm.

"We were directed to a stand-by point because of the access difficulties. The track had to be shut and the railway made safe," the spokesman said.

"The boy was conscious and breathing but his head injury was the primary concern.

"We had to be especially careful, bearing in mind he had been put on a spinal board. We left at 10.41pm and got to the hospital shortly afterwards."

The line was closed for several hours, causing disruption to train services.

One service was cancelled, while others could not reach their destinations. Buses were laid on for passengers travelling between Blackburn and Clitheroe.

One resident in Union Road said more needed to be done to stop youngsters getting on to the railway.

"The access to the viaduct needs to be made more secure because there are often kids getting up there and it is too dangerous," she said.

Transport police are investigating the incident. Anyone with information should call 0800 405040.