BEIJING, Aug. 14 (Xinhua) -- China's press watchdog has penalized or closed 348 websites on the grounds they were publishing pornographic novels.

Forty on-line novels were judged to have "extremely pornographic content, causing great harm to the psychological development of young people," said a press release of the General Administration of Press and Publication (GAPP).

The on-line publication of pornographic novels violated laws and regulations, such as the Measures on the Administration of Internet Information Services and Regulations on Publication Administration, it said.

"The spread of pornographic novels has disturbed the order of on-line publishing and disrupted social order."

The government stepped up an anti-pornography campaign in April, targeting illegal on-line activities, such as distributing pornographic material and organizing strip shows, to purge the web of sexually explicit images, stories, and audio and video clips.

By mid-May, the police had dealt with 244 cases and arrested 270 people in connection with on-line pornography.

The number of Internet users in China reached an estimated 123 million in mid-2006. About 15 percent, or 18 million, are believed to be under the age of 18.