A 15-year-old girl has been killed after being hit by a train at a foot crossing.

Police are investigating what they said looks to be a "tragic accident".

The girl, who has not been named, died after she was struck at Johnson's Footpath Crossing in Bishop's Stortford, Hertfordshire, at around 11.45am yesterday.

British Transport Police (BTP) said she was pronounced dead at the scene.

Network Rail (NR) said investigations were carried out on the crossing immediately after the incident and showed no faults with the safety measures in place.

Flashing lights, audible warnings and signalling systems were all operational, a spokesman said, and there were no problems with the fence and gate at the crossing.

"The crossing was tested immediately afterwards, as always happens when something tragic like this happens," he said.

"The crossing was shown to be in full working order."

An investigation examining the full circumstances surrounding the teenager's death, who is thought to be from Bishop's Stortford, is being carried out.

Both Network Rail and British Transport Police are treating it as accidental.

BTP said: "The incident is being treated as a tragic accident and it has been declared non-suspicious." An on site investigation had been completed and the crossing was reopened shortly after the incident because it was in full working order, the NR spokesman added.

NR is also co-operating fully with the Rail Accident Investigation Branch, which is involved in examining the circumstances surrounding the teenager's death.

The Johnson's Footpath Crossing, which is separated from the footpath with a fence and gates on both sides, has signposts detailing safety instructions.

One shows a red and green traffic light and reads: "If no light - proceed with caution."

Underneath is another sign that says: "Cross only when green lights shows" and "cross quickly".

A further sign says: "Do not cross when red lights show."

A traffic light sits behind the fence, just a few feet from the railway track.

On December 3 2005, Olivia Bazlinton, 14, and Charlotte Thompson, 13, died at nearby Elsenham station, a few miles from Bishop's Stortford, when they were hit by a train.

NR is to be prosecuted over their deaths, the Office of Rail Regulation (ORR) has announced, for alleged breaches of health and safety law.

The girls used Elsenham station footpath crossing to reach the station platform. The station's footpath crossing was fitted with warning lights and yodel alarms.

A London to Cambridge train passed over the crossing with the red lights and yodel sounding - a warning for foot passengers not to cross.

After the train passed, the lights remained on and the alarms continued to sound as another train, travelling to Stansted airport in Essex, was going to pass through the station. The girls opened the wicket gates and walked on to the crossing.

They were both struck by the Stansted train and killed.

The ORR said NR faced two charges under the Management of Health and Safety at Work Regulations 1999 and one charge under the Health and Safety at Work Act 1974.

The first hearing is due to take place at Chelmsford Magistrates' Court in Essex on January 31.