BEIJING (Reuters) - Chinese police said on Saturday that it has closed 1,100 social media accounts, along with 31 websites, this year for unlawful activities such as trolling or blackmailing, the official Xinhua news agency reported.

The police found that some social media accounts on Tencent’s Wechat and Sina-owned Weibo fabricated accusations against companies and individuals, Xinhua said, citing the Ministry of Public Security.

These accounts then posted negative information online and demanded a ransom in exchange for deleting the posts, Xinhua said.

China’s strict 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 authorities this year have shuttered social media accounts for reasons that range from posting lewd content or sensationalist celebrity gossip to articles deemed politically incorrect by censors.

In November, the country’s top cyber authority scrubbed 9,800 social media accounts of independent news providers deemed to have posted sensational, vulgar or politically harmful content on the Internet.

The police also investigated 28 cases involving paid online trolls or ghostwriters hired to post online content and arrested 67 suspects, Xinhua said.