China's top cyberspace regulator said on Tuesday that it has penalized a widely used news app Toutiao, owned by tech giant ByteDance, for presenting "harmful information" on its main trending list.

The Cyberspace Administration of China said in a release that the news app had failed to fulfill its primary responsibility for content management.

In addition to "surfacing problematic items on the main hot-search list", the platform also "pinned related topics at the top of web pages", which "undermined the online ecosystem, the release said.

Under CAC guidance, the Beijing municipal cyberspace regulator recently summoned responsible managers at Toutiao, ordered rectification within a set timeframe, and required the platform to "strictly hold relevant personnel accountable", in line with relevant rules.

"A clean and sound cyberspace and a healthy online ecosystem serve the people's interests," the top regulator said.

It added that the cyberspace authorities will continue to "target prominent violations that damage the online ecosystem", and press websites and platforms to shoulder their primary and social responsibilities in content management.

Starting Saturday, the CAC announced a series of penalties against several leading social media and short-video platforms — including Weibo, Kuaishou, and UC Browser — for breaches that regulators said "undermined the online ecosystem".

According to the regulator, the platforms were found to have hyped up celebrity scandals and illegally displayed information from "extremely sensitive cases", including content involving cyberbullying and minors' privacy.