BEIJING, Jan 1 China arrested more than 5,000 people in a crackdown on Internet pornography in 2009, officials said, vowing tougher online policing in the new year as a key element of “state security”.

China maintains strict censorship of the Internet to curb what the government deems to be unhealthy content including porn and violence — an effort that has become known as the “Great Firewall of China”.

Authorities in December offered rewards of up to 10,000 yuan ($1,465) to Internet users who report websites that feature pornography.

According to figures published by the ministry of public security late on Thursday, 5,394 people were arrested last year under the Internet porn crackdown, and 9,000 illegal porn-related sites were shut down.

The ministry, in a statement on its website, did not specify if all of those arrested were later prosecuted.

It said it would “strengthen punishment for Internet operators that violate the laws and regulations” in the coming year and “severely punish operations that have serious problems with harmful information”.

“Purifying the Internet environment and cracking down on Internet crimes is related to long-term state security,” the ministry said.

Internet use has expanded at a dizzying pace in China, which now has the world's largest online population with at least 338 million users.

The government is concerned that left unchecked, the Internet could become a means for ordinary citizens to spread information harmful to society — including ideas that are critical of the communist authorities.

China has blocked several social networking sites such as Facebook and Twitter. Citizens can only gain access to such sites by using proxy servers.—AFP