A 15-year-old boy is in a stable condition in hospital after a daredevil prank went horribly wrong last night.

The teenager from Benwell was among a group of children, most of whom were teenagers, who climbed onto steel girders underneath the Scotswood Bridge in Newcastle in what in believed to have been a dare.

After frantically clambering onto the girders the boy slipped and fell 20ft from an open service hatch onto the bridge's central support 20 feet below.

He landed on a three feet wide ledge which was 40ft above the River Tyne

Two girls were also left stranded underneath the bridge while their friend screamed in pain.

The bridge was closed for more than two hours while firefighters risked their own safety carrying out a dangerous abseil rescue to save the children.

The injured boy, who has not been named, was carried out of the shaft before being strapped to a stretcher and lifted on to the bridge where he was placed in an ambulance and taken to hospital. His head injuries were described as serious, but not life threatening.

The two girls were taken to hospital but were believed to have been released.

Rescuers were forced to abseil from the top of the road bridge down to the three-ft wide block to help the youngsters. Paramedics also had to abseil down to assess the young boy's condition.

A specialist aerial ladder platform which had a metal cage attached to the end was lowered from the bridge to pluck all the youngsters to safety.

A fire rescue boat was also on standby to fish out anyone who fell in to the river.

"This group seemed to have been mucking around an some sort of prank, but their foolhardy action not only put their lives in danger, but also risked the lives of those sent to rescue them," said Peter Trevithick, divisional officer from Gosforth Fire Station.

"Any rescue that involved hanging high over a choppy river is obviously dangerous and the firefighters we're extremely brave in their actions. We would also like to thank the paramedics and police who also ensured this was dealt with effectively."

Station officer Tim McArdle, of Tyne and Wear fire brigade, said: "The children had got access to the bridge from the river bank via an internal structure.

"There are concrete pontoons about 30m from the river bank and about 60m high.

The children had got in through a girder, which is a confined space in itself, and crawled along there to a part which was above the pontoon.

"The lad has then fallen about 20ft. Because of the nature of the pontoon normal fire brigade ladders were not going to gain access to it. We got crews from Hebburn and South Shields who are rope rescue and abseil specialists to assist."

A spokesman for Northumbria Police said: "Police are making further inquiries in to the matter.

"He had slipped and fallen and we are currently making further inquiries into the incident."

Updated: 14.57 Wednesday, June 13

Updated: 11.27 Wednesday, June 13