Newsround discovered several videos not fitting for children, including one displaying how to sharpen knives.
Another had personalities from children’s cartoon Paw Patrol on a burning plane.
YouTube has been scrutinized for using algorithms preferably than human curators to select what appears on YouTube Kids.
In 2015, two child safety crowds accused after disturbing videos were obtained on the YouTube Kids app.
YouTube said it needed to “do more” to stop inappropriate videos being seen by children.
Newsround had obtained for five children to meet Google’s Katie O’Donovan.
They spoke about distressing videos they had observed on the main YouTube website and app.
The videos included images of clowns with blood on them, scary advertisements and broadcasts telling them someone was at their door.
Ms O’Donovan said she was “very, very sorry for any hurt or discomfort” conceived by the videos.
“We’ve actually built a whole new program for kids, called YouTube Kids, where we take the best content, stuff that children are most engaged in and put it on there in a packaged up place just for kids,” she said.
But Newsround reported that it had discovered inappropriate videos there too.
They included Mickey Mouse figures with guns and children’s characters being injured.
YouTube said it had a change of processes in place to try and prevent improper material appearing on its platforms.
It told Newsround: “We have seen meaningful investment in building the right tools so characters can flag that content, and those flags are examined very, very quickly. We’re also beginning to use machine learning to recognize the most harmful content, which is then automatically evaluated.”
Newsround asked whether there was too much content for the program to check.
Google said that securing YouTube remained an open platform “comes with real calls because the content is uploaded and it is life”.
“It is a difficult tension to get right,” YouTube told Newsround, adding: “It is a difficult situation because things are propelling so, so quickly.”
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