Seven people have been detained in the booming southern city of Shenzhen for allegedly involving in online pornography that served overseas Internet users, Chinese Ministry of Public Security has said.

Police in Shenzhen cracked on May 24 the seven-member ring that were accused of providing online strip shows to registered overseas members, the ministry said.

The mastermind of the ring, a woman surnamed Su, had been accused of recruiting 12 women to give sexually-provocative performances since April 2006 and collecting as much as 50,000 yuan (about 6,500 U.S. dollars) from overseas contacts.

The ring ran 12 websites that could only be accessed from outside the border, and their servers were all located in Taiwan and Hong Kong, according to the ministry.

China has stepped up its anti-pornography efforts in the cyber space since it launched a six-month crackdown campaign in April.

The campaign by the ministry and nine other government departments targets illegal online activities such as distributing pornographic materials and organizing cyber strip shows. It hopes to purge the web of sexually-explicit images, stories, and audio and video clips.

By mid-May, Chinese police had cracked 244 cases and detained 270 suspects involved in online pornography, the ministry said.