BEIJING, Aug. 6 -- Chinese police have launched investigations into the recent spread of several obscene video clips online, following action against a high-profile sex video last month.

The National Office Against Pornographic and Illegal Publications has told police to investigate cases including two videos which went viral this week and which are believed to have been filmed in the eastern Zhejiang Province and the southwestern Sichuan Province.

Police have tracked down the suspects involved and the cases are under further investigation, the office said in a statement on Thursday.

Beijing police last month detained four people in connection with the dissemination of a sex video believed to have been filmed in the fitting room of a Uniqlo clothes store in the city's upmarket Sanlitun district.

In Thursday's statement, the office denounced the spreading of such obscenity online as unethical, saying it deserved serious punishment.

It called on local authorities to organize checks and punish websites for violations.

The office also encouraged the public to report offenses via the telephone hotline 12390 or social media accounts set up for the purpose.