London: Sex offences by users linked to social networking sites Facebook or Twitter have rocketed in the last four years.
A Mirror investigation also revealed that paedophiles are increasingly logging on to the social networking sites to target children.
A total of 1,642 cases since 2009 have been reported to police where the sites played a part in the commission or aftermath of a crime.
Statistics obtained under freedom of information laws have revealed the number has more than quadrupled from 139 four years ago to 614 last year.
The investigation found that more than half the 1,395 victims of all offences – apart from rape – were below the age of 16.
And the number of alleged rapes involving Facebook and Twitter rose from 22 in 2009 to 117 last year.
Detectives say personal information on the sites is being used by predators to identify vulnerable girls or women and gain their trust.
The figures, released by 25 police forces across England and Wales, suggest that some victims only found out what had been done to them from gloating messages left on Facebook by their attackers.
Under current terms and conditions, no one under 13 is permitted to hold a Facebook account. And those aged 13 to 18 are given protection limiting what details they can post.
But a survey of 4,000 children carried out by Prof Andy Phippen, of Plymouth University, found that nearly 40 percent of primary school pupils are already on Facebook, the report added.