A new report shows that some 1,400 minor girls are annually blackmailed into sex slavery in the Netherlands by male traffickers.

According to a report by the Dutch newspaper Algemeen Dagblad, traffickers first attempt to win the affection of a vulnerable teen and then secure a sordid footage of their tryst with their underage female victims in order to blackmail them into sex slavery.

The report, citing Carolien van den Honert, a policy officer at the human rights charity Humanitas, said that the traffickers are mostly Moroccans, Turks, Antilleans, and Roma, and that they earn up to €800 per day from pimping teenage prostitutes.

She added that all the sex traffickers have one thing in common: “They are real criminals… In many cases, they are part of a larger network that also engages in weapons or drug trafficking.”

According to researcher Gideon van Aartsen, apart from blackmailing the minors through footage secretly recorded, traffickers may also force their victims to lure their fellow underage friends into the business if they wish to work less.

Watch Nederland, an initiative that coordinates with police to fight the sexual exploitation of children, has been attempting to destroy the online trade by discouraging potential customers.

The initiative reportedly sets up fake ads for teenage girls, and once a customers approaches, he is sent an email that reads: “Watch Nederland knows you now, make sure we never meet you again.”

Official figures show that only one out of 10 underage girls is receiving assistance, an alarm that has prompted police to take steps to combat the growing epidemic, including through the training of personnel to swiftly recognize distress signals from girls on the streets.

Earlier this month, the Dutch government blamed Italy and Greece for allowing two-thirds of refugees and asylum seekers stepping on their soil to slip deeper into Europe by failing to register their arrival.