Apple and Alphabet-owned Google have warned Amazon after the companies learnt that sexually explicit photographs can be accessed by children on the popular Kindle app. The companies called on Amazon to strengthen its content moderation. “We’ve shared these concerns with the developer and are working with them to ensure their app is compliant with our guidelines,” a Reuters report cited Apple as saying. Google, on the other hand, said that “Google Play does not allow apps that contain or promote sexual content and we’ve been in contact with the developer on this issue.” Reuters reported children can access and view online volumes of photographs of naked women. Some appeared to show women and men engaging in sexual acts. Google and Apple said their concerns were around policy violations. The news agency cited two families as saying that their “pre-teen sons downloaded the explicit material via Amazon’s Kindle Unlimited e-book subscription service and viewed the full-colour photographs on the Kindle iPhone app.” The report also mentioned that pornography also is available through Amazon’s Kindle online store and viewable on versions of the Kindle app. Here’s what Amazon has too say Amazon has said that it is reviewing all of the available information. “We’re committed to providing a safe shopping and reading experience for our customers and their families and we take matters like this seriously. We are reviewing all of the available information and are taking action based on our findings,” Amazon is quoted as saying. The adult material is linked to the self-publish feature through Amazon’s Kindle Direct Publishing arm. Authors can self-publish their books nearly instantaneously through Amazon and may designate the content as available for the Kindle Unlimited service. According to Amazon’s terms for its self-publishing arm, it can refuse to sell content it deems “offensive or inappropriate,” which may include content that “contains pornography.” There are no parental controls available for the Kindle Unlimited service, Reuters said.