One in five youngsters has been subjected to unwanted sexual advances outside the home, according to a new survey.

Researchers at the University of Huddersfield sent out questionnaires to 2,400 schoolchildren.

The reponses ranged from relatively minor incidents to sexual advances and attempted abductions.

The authors say the study is the first of its kind to try to discover the extent of abuse, and attempted abuse, of children by strangers.

Of the 2,400 schoolchildren aged between nine and 16, asked, 22% said they had experienced unwanted sexual attention.

• 9% said the incident had involved by a stranger

• Nearly half of the incidents reported were indecent exposure

• Four children reported they had been the victim of an abduction

• 40 children managed to escape an attempted abduction

The BBC's Andrew Hosken said children's protection charities such as Kidscape had found that publicity surrounding cases such as that of missing Cambridgeshire schoolgirls Holly Wells and Jessica Chapman and other high-profile disappearances had increased parents' concerns.

News of the university's study came a month after it was announced that teachers could face disciplinary action if they fail to report suspicions that a child is being abused.

The law is being tightened to help protect vulnerable children after a campaign by the former education secretary Gillian Shephard.

New recommendations aimed at ending miscarriages of justice in child abuse investigations are in the hands of the Home Office.

The BBC learned earlier this year that a new guidebook, drawn up by eight senior officers, could be used by police forces across the country.