BEIJING, CHINA: China shut down 44,000 Web sites and homepages and arrested 868 people last year in a campaign against Internet porn which will continue until the end of this year's Beijing Olympics, Xinhua news agency said on Wednesday.

China launched a crackdown on online pornography and "unhealthy" Web content after Chinese President Hu Jintao said the country's sprawling Internet posed a threat to social stability.

Rights groups have said the campaign has been used as a thinly veiled pretext to crack down on dissent and round up online dissidents ahead of the Olympics.

Xinhua said authorities had also investigated 524 criminal cases involving online porn and "penalised" another 1,911 people.

Some 440,000 "pornographic messages" had also been deleted, the agency said.

China has attempted to stifle online criticism of the ruling Communist Party and discussion related to sensitive topics such as Tibet and Taiwan by ordering Web sites to register with authorities.

Authorities registered 199,000 Web sites last year, Xinhua said, but refused 14,000 for failing to get official registration or to apply for official approval.

China employs tens of thousands of human Internet censors and a vast network of filters to control online information.

The anti-pornography campaign would continue until September, Xinhua said, "after the Beijing Olympic Games end".

China last month said it would crack down on video-sharing Web sites, and allow only state-controlled sites to post video content online in new restrictions effective from Jan. 31.