BEIJING, December 30, 2010 (AFP) - China said Thursday that authorities had shut down more than 60,000 pornographic websites as part of a year-long crackdown on lewd online content, as Beijing moves to tighten control over the Internet.

"By the end of November, we had inspected 1.8 million websites, and closed down more than 60,000 unsound websites that spread porn," Wang Chen, minister for the press office of the State Council, China's cabinet, told reporters.

He added that authorities had jailed 58 people for at least five years in the crackdown on lewd online and mobile phone content that was launched in December last year.

China, which has the world's largest online population with 450 million users, operates a vast web censorship system sometimes known as the "Great Firewall of China".

The government says it censors the Internet to curb "unhealthy" content including porn and violence, but critics counter that it is mainly trying to prevent the posting of information that challenges the ruling Communist Party.

Still, emboldened Chinese web users have made the Internet a new forum to, among other things, express opinions in a freewheeling way rarely seen in the strictly government-controlled traditional media.

Wang said the crackdown would continue as violence and pornography would not disappear from the Internet.

"This special operation to rectify online pornography and vulgar content has not come to an end -- this is a protracted war," he said.