China’s cyber authority has taken down 9,800 social media accounts of independent news providers deemed to have posted sensational or politically harmful content on the Internet, it said late on Monday.

China’s online censorship rules have tightened in recent years with new legislation to restrict media outlets, surveillance measures for media sites and rolling campaigns to remove content deemed unacceptable.

The Cyberspace Administration of China (CAC) said in a statement that the campaign, launched on Oct. 20, had erased the accounts for violations that included "spreading politically harmful information, maliciously falsifying (Chinese Communist) party history, slandering heroes and defaming the nation’s image."

CAC also summoned social media giants, including Tencent’s Wechat and Sina-owned Weibo, warning them against failing to prevent "uncivilized growth" and "all kinds of chaos" among independent media on their platforms.

"The chaos among self-media accounts has seriously trampled on the dignity of the law and damaged the interests of the masses," CAC said.

The term "self-media" is mostly used on Chinese social media to describe independent news accounts that produce original content but are not officially registered with the authorities.