A 15-year-old girl was subjected to an hour-long sex attack before being dumped in a canal, police said.

The girl, was walking in Hall Lane, Shipley, just after midnight yesterday when she was grabbed from behind by a man and dragged into the church yard of Christ Church, in Church Street, before being subjected to a serious sexual assault.

He then walked her along Thackley Old Road towards a playground, before taking her down a footpath towards the canal, a distance of about three-quarters of a mile from where she was initially attacked.

The girl, from Shipley, was then subjected to a further serious sexual assault on the footpath about 30 metres from the canal.

She was then pushed into the canal and her attacker walked away from the scene.

He is described as white, about 6ft tall, stocky, with a chubby face. He had dark, brown short hair, and a deep Scottish accent. He was believed to be wearing a checked shirt, black jeans and trainers.

The girl managed to climbed out of the canal and alert the police.

A police spokesman said the victim was badly traumatised by the attack and was being looked after by specially trained officers.

Detective Superintendent Tim Forber, who is leading the investigation, said: "This was clearly a very serious attack on a terrified young girl and it is vitally important that we catch this man.

"We urgently need to speak to anyone who was in the area between midnight and 2am and saw anything suspicious or saw the victim or a man answering this description.

"Even what may seem like the most insignificant bit of information could be important to this investigation and I would urge anyone who was in the area or who has any information to get in touch with us immediately.

"The incident room at Javelin House Police Station can be contacted on (01274) 376100 or information can be passed via Crimestoppers on 0800 555 111.

Alternatively people can pass on information by texting 07786 200806 and starting the message with the word "Shipley".