A 13-year-old boy was put on the sex offenders' register, on Monday, for two-and-a-half years, after a UK-wide paedophile swoop found more than 300 paedophilic images on his home computer. The teenager admitted to nine counts of possessing indecent photographs, and has been given an 18 month supervision order, on condition he attends a rehabilitation course. Contrary to reports, Greater Manchester's Obscene Publications Unit confirms he is the second youngest person to have been put on the sex offenders' register -- the youngest being a 12-year-old convicted in Manchester for indecent sexual assault. A dawn raid in March dubbed Operation Appal resulted in the immediate arrest of the teenager, after 326 indecent images were found on the hard drive of his PC. A total of 48 warrants and 36 arrests were executed as a result of the operation, six of those being boys under the age of 17. Serious cases of child abuse were also uncovered by Appal. "It's extremely disturbing that children of a young and impressionable age can access such damaging material on the Internet," said inspector Terry Jones, of Manchester's Obscene Publications Unit, who co-ordinated the UK wide investigation. "No one at this stage has any idea of the long term effects on young people being able to access such inappropriate material." District Judge, James Prowse, sitting at Teeside Youth Court, said that the boy, who cannot be named for legal reasons, had become an "unwitting victim" of a paedophile ring peddling child pornography over the Internet. Half a dozen of the images found on his computer were of babies, as young as one-year-old, engaged in sexual acts. The court heard how the boy had initially logged onto an Internet chatroom in search of teenage girls of a similar age. The judge told the boy: "I accept that you did not go onto the Internet looking for this material -- your initial reason was to look for innocuous teenage chatrooms. What you found, you found by accident. What you then did was pursue it". Operation Appal was the third investigation launched by the Greater Manchester police force into the distribution of obscene material over the Internet. A three-month investigation resulted in a series of raids across the country, at 7am this morning, with the help of 25 forces across England, Scotland and Wales. Take me to ZDNet's Net Crime Special Have your say instantly, and see what others have said. Click on the TalkBack button and go to the ZDNet News forum. Let the editors know what you think in the Mailroom. And read other letters.