BRUSSELS, Belgium: TikTok faces possible changes to its recommendation algorithm in Europe after EU regulators accused the social media platform on November 6 of violating the bloc's online content rules by repeatedly directing users toward similar videos, potentially harming their mental health.

The European Commission said TikTok had failed to take adequate measures to address the so-called "rabbit hole" effect of its recommendation system, which keeps users engaged through a continuous stream of related content.

The platform's Chinese owner, ByteDance, could face a fine next year of up to 6% of its global annual turnover unless the concerns are resolved, regulators said.

The charges come amid growing international scrutiny of social media algorithms and their potential impact on children's mental health. Several governments have imposed or are considering restrictions on social media use by minors.

The Commission, which serves as the EU's technology regulator, said TikTok had failed to implement proportionate, reasonable and effective measures to mitigate the risks associated with its recommendation system.

It warned that repeated exposure to videos dealing with sadness, isolation or body image could negatively affect users' mental health.

TikTok rejected the allegations.

"The Commission has made a series of statements that are fundamentally inaccurate and distort our platform's architecture and our commitment to user safety," the company said in a statement.

"We have a strong record of protecting our community while giving users direct and intuitive control over their content experience."

EU tech chief Henna Virkkunen said the platform's algorithm could repeatedly steer users toward similar material, making it difficult for them to break away from particular types of content.

"Every time a user scrolls or likes a video on TikTok, the algorithm serves more of the same leading users down rabbit holes they cannot easily escape from," Virkkunen said in a statement.

"Today's preliminary findings show again that TikTok needs to step up its efforts to protect users' well-being, including those of minors," she said.

The Commission said TikTok needed to change its business model in Europe, including redesigning the algorithm behind its personalized 'For You' feed.

Regulators called for the platform to place greater emphasis on users' explicitly stated preferences, make its content controls easier to access and use, and conduct regular testing of its recommendation system.

The preliminary findings were issued under the EU's Digital Services Act, which requires large online platforms to take stronger measures against harmful and illegal content.

They form part of a broader investigation into TikTok's operations in Europe.

In February, EU regulators also issued preliminary findings concerning what they described as TikTok's addictive design features, inadequate protections for children and obstacles faced by researchers seeking access to public data.

TikTok rejected those earlier findings as "categorically false" and said it would challenge them.

The Commission is separately examining whether the recommendation systems used by Meta Platforms' Facebook and Instagram create similar "rabbit hole" effects.