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China's top anti-pornography office on Thursday announced its latest mission: a campaign to remove amateur sex videos from China's social media.

Long intolerant of obscenity online, Beijing authorities are now trying to keep China's cyberspace clean at a time when it has become easier for people to use mobile phone to make sex videos and use social media and cloud storage to share such content.

In July, a sex video taken with a mobile phone inside a fitting room of the clothing retailer Uniqlo in Beijing spread quickly in China's social media. Police have detained four people on suspicion of spreading the obscene content.

On Wednesday, sexual scenes were somehow aired on a giant display screen at a shopping mall in the eastern city of Lishui, and clips of the footage spread online, prompting police to investigate who was spreading the content, according to media reports.

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Also on Wednesday, a homemade video clip of sexual acts in the southwestern city of Chengdu spread on China's Twitter-like Weibo, and police have detained one suspect on suspicion of spreading the video, local authorities said.

Citing these three incidents, the Office Against Pornography and Illegal Publications said it is demanding that government authorities at all levels throughout China take immediate action whenever such cases arise, and to "resolutely" punish those who upload and host the content. The office also called on the public to report such content through a hotline.