A SEX fiend who raped a 17-year-old girl at knifepoint after ordering her to strip could strike again, police warned today.

The teenager was grabbed by the man as she walked past him while taking her dog for a walk in Moses Gate Country Park, Farnworth.

The girl was dragged into undergrowth and raped as the attacker held a knife at her throat.

The screaming teenager's ordeal lasted for up to 15 minutes before she jumped naked into the River Croal to escape and waded to the other side.

Detectives today released an e-fit of the sex fiend as they advised women to be extra vigilant and avoid secluded tracks in the park.

The teenager arrived in the park at about noon on Tuesday to walk her Staffordshire Bull Terrier and spent approximately two hours strolling in the afternoon sunshine.

Police said that at about 2pm she saw a man leaning against the railings near to the Rock Hall Visitors Centre.

As she walked past him into the wooded area with her dog, he grabbed her around the waist and threatened her with a knife.

The attacker pushed her into the woods and made her remove her clothing before he raped her.

She only managed to escape by wading waist-deep across the river to the visitors centre. Two women who were walking nearby then phoned the police.

Detectives say the rapist was a white man, in his late 20s to early 30s, around 5ft 6ins and of medium build.

Det Insp Andy Aston, of Bolton CID, said a team of detectives was now working "around the clock" in the hunt for the rapist.

He said: "This was a vicious attack in broad daylight and we need to catch this man as soon as possible.

"This man is a danger to the public and he could strike again at any time. But I would also like to re-assure people that incidents of this nature are relatively rare.

"The victim is very traumatised, but she is being very brave and is co-operating with the police inquiry to help us catch this man.

"We would advise anyone using the park, particularly women, to be aware of their surroundings and public safety.

"There are a number of secluded tracks in the park and, if anyone sees anybody acting suspicious contact the police patrols.

"We would also ask anyone who may have an idea who the attacker is, or any suspicions at all, to call us."

Detectives believe the man is local and are scouring their lists of sex offenders for possible suspects.

Extra uniformed and mounted officers have been drafted into the park to reassure the public. A mobile police station has been set up by the Rock Hall Visitors Centre until Sunday evening.

Police are appealing to anyone who was in the park between 10am and 4pm on Tuesday to come forward. They are keen to trace a man in his 70s wearing a green jacket and glasses, who was walking a golden Labrador believed to be called Ben.

Officers would also like to speak to a woman in her 20s wearing a white coat and a pushing a buggy with a two-year-old child, which was seen near to the visitors centre at 2.20pm.

The victim remembers seeing the pensioner in the park and officers think he may have vital information in the hunt for the sex attacker.

They have already appealed for a witness in his 50s with grey hair walking close to the nearby Farnworth Cemetery at 2.20pm to come forward.

The rape victim was interviewed at Bolton Central Police Station by specially trained officers yesterday.

If you have any information call Farnworth CID on 0161 856 5853, or Crimestoppers on 0800 555 111.