One male and one female, the duo will pop up on a user's browser and walk, cycle or drive across the screen warning the user to stay away from illegal Internet content.

Starting on Sept 1, the cartoon alerts will appear every half-hour on 13 of China's top portals, including Sohu and Sina, and by the end of the year will appear on all websites registered with Beijing servers, the Beijing Public Security Ministry said in a statement on Tuesday.

China stringently polices the Internet for material and content that the ruling Communist Party finds politically or morally threatening. Despite the controls, nudity, profanity, illegal gambling and pirated music, books and films have proliferated on Chinese servers.

The animated police appeared designed to startle Web surfers and remind them that the authorities monitor Internet activities closely.

The cartoon officers, designed for the ministry by Sohu, will issue a text warning to surfers to abide by the law and give tips on Internet security as they move across the screen, the statement said.

If Internet users need police help, they can click on the cartoon images. They will then be redirected to the authority's website.

'We will continue to promote new images of the virtual police and update our Internet security tips in an effort to make the image of the virtual police more user-friendly and more in tune with how Web surfers use the Internet,' the statement said.

China has the world's second-largest population of Internet users, with 137 million people online, and is on track to surpass the United States as the largest online population in two years.

ASSOCIATED PRESS