More than 260 suspected child sex groomers are under surveillance in West Yorkshire.
Police have revealed the shocking figure, but officers believe the 263 predators on their radar are just the tip of the iceberg.
About 380 youngsters, as young as 11, are feared to be at imminent risk of falling into the clutches of groomers.
The figures have been revealed as the force today launched a campaign to tackle the problem.
The Know the Signs campaign aims to highlight what tell-tale signs might indicate a youngster is being groomed.
Temporary Assistant Chief Constable Ingrid Lee, who is in charge of the initiative, said: “We all have a responsibility to confront this terrible crime and to protect those who are the most vulnerable in society.”
She said the force arrested more than 100 people last year on suspicion of grooming offences. There are 40 ongoing investigations into the crimes.
Of the 263 identified suspected groomers still at large, 57 per cent are Asian men.
But Mrs Lee said that figure may be skewed because of the greater focus on the Asian community as a result of high-profile court cases.
She said the vast majority of child abuse was carried out by white men, adding: “The Asian community recognises that this is an issue and we are working with them on it.
“But there are people who are serial abusers who are very clever and secretive and if we don’t focus on every community, we will miss them.”
The campaign uses radio adverts, posters and the internet to tell people what to look out for.
Children spending excessive amount of time online and being secretive about their activities could be a giveaway.
A child who is regularly going missing or truanting from school may also be at risk.
Mrs Lee added: “We are absolutely committed to raising people’s awareness and tackling this dreadful abuse of our young people.”
Leeds charity Genesis, whose Isis project supports children at risk of sexual exploitation, welcomed the campaign.
A spokeswoman said: “We support initiatives which help raise awareness amongst the Leeds community around child sexual exploitation. We see the harmful impacts this form of exploitation has on young people in the city and recognise the need for us all to work together to support and protect young people.”
For more on the campaign visit www.westyorkshire.police.uk/cse