EU tech regulators charged social media platform TikTok on Friday with breaching the bloc's online content rules, telling ​it to fix the so-called "rabbit hole" effect of its recommender system, which attract users' attention ‌to a constant stream of similar videos. TikTok's Chinese owner ByteDance risks a fine next year of up to 6% of its global annual turnover unless it can resolve the issue, the regulators said. Social media companies are under pressure to modify their algorithms amid growing ​concerns worldwide that their platforms are contributing to a mental health crisis among children, prompting some ​governments to impose or consider bans for underage users. The European Commission, which acts as ⁠the EU tech regulator, said it issued charges known as preliminary findings to TikTok after the company failed ​to implement proportionate, reasonable and effective mitigation measures to address the risks. It said endless and repeated exposure to ​content about sadness, isolation or body image can have a detrimental impact on users' mental health. TikTok rejected the accusations. "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." The Commission said TikTok needs to change its business model in Europe. Read More: Apple's predictive text restrictions include 'Dictator Trump' and 'Sleepy Joe,' researcher finds "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," EU tech chief Henna 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 ​needs to change the design ​of its 'For You' feed ⁠algorithm and should rely more on users' explicit preferences, increase the accessibility and usability of user controls and regularly test its algorithm, among other changes. The Kospi plunged more than 8% just soon after the market opened today, Broader investigation into TIKTOK The charges ​are under the EU's Digital Services Act which requires big online platforms to ​do more to ⁠tackle harmful and illegal content on their platforms. The latest charges are part of a broader EU investigation into TikTok. EU regulators charged TikTok in February over what regulators said were the platform's addictive designs, inadequate efforts to protect children and making ⁠it ​difficult for researchers to request access public data. TikTok said at the ​time that those preliminary findings were "categorically false" and it would take steps to challenge them. The Commission is separately investigating so-called rabbit hole effects caused ​by Meta Platforms' (META.O), opens new tab Facebook and Instagram recommendation systems.