The European Commission announced on Thursday investigations into YouTube and TikTok.
The move comes as the EU works to rein in tech giants after the passing of the Digital Services Act (DSA), which came into effect in August.
What did the EU say to YouTube and TikTok?
The EU's executive branch said that it had sent formal requests for information to the two firms. The companies have until November 30 to respond.
It said it wanted to know what measures YouTube and TikTok had implemented to comply with the DSA, especially with regards to the protection of children.
The commission said it asked for information on the firms' "obligations related to risk assessments and mitigation measures to protect minors online, in particular with regard to the risks to mental health and physical health, and on the use of their services by minors."
The commission said that it will announce next steps based on an assessment of the companies' replies, which could include the "formal opening of proceedings."
What is the Digital Services Act?
The DSA is part of a set of EU measures designed to regulate the tech industry. It demands that firms do more to counter the spread of disinformation and illegal and harmful content.
The law has also banned targeted advertising to people aged 17 and under.
Under the act, platforms can face fines of up to 6% of global turnover for violations.
TikTok is owned by Chinese company ByteDance and is popular among younger users. YouTube is owned by Google's parent company, Alphabet.
In August, the EU commissioner in charge of the internal market, Thierry Breton, said that "child protection will be an enforcement priority" for the DSA.
The commission said that it had already sent TikTok a request for information on October 19 "concerning the spread of terrorist and violent content and hate speech" and "the alleged spread of disinformation" related to the war between Israel and Hamas.
sdi/nm (AFP, EFE)