Children who watch cartoons and others kids programmes on YouTube are an average of three clicks away from videos with explicit content, a study has said.
An study of YouTube's "suggested videos", which sit alongside children's favourites, found that it was easy to access clips including nudity and violence.
The study was released by online security firm Kaspersky Lab to mark Safer Internet Day, the Telegraph reports.
Kaspersky's David Emm said that it is 'worrying to see just how simple it is for children to access videos of an adult nature on YouTube.'
According to the paper, there have been separate calls from campaigners to give children as young as five lessons in how to use the internet safely.
The call comes amid fears that children are increasingly exposed to online pornography and forced to send indecent images of themselves to others, the report said.