More than 370 people were reported to Sussex Police for indecent images offences over the last three years, according to figures obtained by the NSPCC.
And of the investigations during that time where the age of the defendant was recorded, 13 were under the age of 18.
The total number of offences reported to all 45 police forces across the UK has nearly tripled, rising from 4,530 in 2013 to 10,818 in 2015. Of those 2,031 were under the age of 18.
The NSPCC is urging parents to talk to children about the risks of sharing nude selfies on mobile phones and social media as this may be partly fuelling the rise in offences by under-18s.
An NSPCC survey recently revealed only half of parents knew that children taking nude selfies were committing a crime.
However, among those children reported to the police may also be young people who have been found in possession of child abuse images. And the big rise in adults caught with indecent images of children shows the demand is still growing.
The NSPCC says that behind all these images is a child who has suffered appalling harm and may still be in danger today. And a significant proportion of those who view child abuse images have an increased risk of acting out their desire to sexually abuse children.
The NSPCC has identified four key areas where urgent action is needed to turn back the tide:
Internet companies need to develop and share technological solutions – and make data about progress removing child abuse images publicly available;
Young people should be able to get nude selfies removed from the internet more easily, as they can often end up in the hands of predators;
Children and young people who have been the victim of these crimes need more easily accessible support to help them recover;
Offenders who are convicted must be offered treatment to reduce their future risk to children.
Peter Wanless, CEO of the NSPCC, said: “Over the last two decades, digital technology has fuelled an explosion in the production and consumption of child sexual abuse images that increasingly involves the streaming of live video.
“Committed leadership from government, and dedicated police operations have made a real difference. But the war on child abuse images is only just beginning. The internet industry must prioritise this issue by committing their expertise and work with the public and voluntary sector to find solutions.”
“As well as pursuing and deterring adults who make and distribute these we must educate children about how to keep themselves safe online and offline and how to get help as soon as grooming or abuse happens. And every child who is the victim of exploitation and abuse should get the support they need to rebuild their lives.”