China has shut down 91 Web sites for pornographic and other "vulgar" content, as well as a political blog portal, since announcing its latest bid to ensure Internet morality, state media said.

China's ruling Communist Party is wary of threats to its grip on information and has conducted numerous censorship efforts targeting pornography, political criticism and Web scams, but officials flagged tougher steps this time.

"Ninety-one websites that included pornography and vulgar content had been closed down from January 8 to 10," the state-run Web portal China (www.china.com.cn) said.

Bullog.cn, a Chinese blog portal with many famous bloggers, including some signatories of the pro-democracy "08 Charter," has been inaccessible since Friday.

Luo Yonghao, the founder of Bullog.cn, confirmed on his own blog that the Web site had been closed because of "amount of political harmful information," citing a notice from government.

The "08 Charter," issued online with the names of 303 Chinese citizens, calls for freedom of expression and association and open elections.

China's latest crackdown on Internet content targeted many big names, including Google, Microsoft's MSN and homegrown market-leading rival Baidu, for undermining public morality.

None of the big names was on the list of 91.