A 13-year-old girl was grabbed by a man who pounced out of bushes as she competed in a cross country championships.

Police launched a major hunt for the suspect, involving the force helicopter, dog patrols and search teams, following the incident at Witton Park, Blackburn.

The teenager was grabbed as she ran through an area of bushes in a field north of the visitor centre.

She fought free from the man's grasp before telling her parents after crossing the finishing line.

The incident occurred as 1,000 athletes from across the North West, including

Blackburn Harriers and Burnley Athletics Club, competed in the Lancashire Athletic Association Cross Country Championships on Saturday afternoon.

Detective Sergeant Gary Dunnagan, of Blackburn CID, said: "There were hundreds of people in the park and the clothing the man was wearing was quite distinctive. Anybody with information should come forward.

"I'm particularly interested to hear from anybody around this thicket as the person will have had to go in and out of it.

"I don't want to alarm people at this stage because we don't know what he was intending to do yet. It may have been somebody confused and unsure of their whereabouts or what they were doing. At the same time, it may have been something more serious."

Organisers of the Lancashire Athletic Association Cross Country Championships said they did not want to comment as a police investigation was under way.

The 13-year-old girl was among 49 runners competing in the under 13s three-kilometre run. It is a well-established route which is lined with stewards and St John Ambulance personnel.

Det Sgt Dunnagan said: "We are not concerned about the marshalling of the course."

He added that the girl had been on her own half way down the field of runners. Shortly after she wriggled free, a group of runners passed through but did not see anything suspicious.

The girl said the man was 6ft tall, white, blotchy and was wearing a black woolly hat, sunglasses, a black puffa-style jacket, dark trousers and black and white trainers.

Mike Linaker, membership secretary of Burnley Athletics Club said he had heard about the attack, but was unable to comment further.

Call Blackburn CID on 01254 353569 or Crimestoppers on 0800 555 111.