YouTube has announced a clampdown on videos that show popular children's TV characters in violent and frightening scenes after it emerged that hundreds of disturbing videos featured on the website.

The online video service, owned by Google, said "inappropriate use of family entertainment characters" would be restricted to adults when they are reported by users.

Investigations have found reams of bizarre videos depicting children's characters in morbid situations appearing on YouTube and on its children-only app, YouTube Kids.

They included Peppa Pig in frightening situations, such as drinking bleach or getting teeth pulled out at the dentist. Other videos include clips of Elsa from Disney’s Frozen and Spiderman fighting other characters in animated clips, while some have sexually suggestive themes.

Under the new rules, such videos will be deemed age-inappropriate, being removed from the YouTube Kids app and blocked from logged-out users or those aged under 18 on the main website.