BEIJING -- China has launched a crackdown against major websites that officials accused of threatening morals by spreading pornography and vulgarity, including the dominant search engines Google and Baidu.

China's Ministry of Public Security and six other government agencies announced the campaign at a meeting on Monday, state television reported, showing officials hauling digital equipment away from one unidentified office.

The meeting "decided to launch a nationwide campaign to clean up a vulgar current on the Internet and named and exposed a large number of violating public morality and harming the physical and mental health of youth and young people," the report said.

The 19 Internet operators and websites named had failed to swiftly cut "vulgar" content and had not heeded warnings from censors, it said.

Baidu dominates the Chinese web search and advertising market with an estimated two-thirds of the audience. Google Inc, the global market leader, is a distant number two in China.

Cui Jin, a public relations official for Google in mainland China and Sun Yao, Baidu's PR representative declined to comment when contacted by Reuters, both saying they were unaware of the announcement. Sina.com was also one of those named.

China's ruling Communist Party is wary of threats to its grip on information and has launched many such censorship efforts before, targeting pornography, political criticism and web scams. But officials flagged tougher steps this time.

The campaign also coincides with Communist Party efforts to stifle dissent and protest as the economy slows and as China enters a year of sensitive anniversaries, especially the 20th year since the bloody crackdown on pro-democracy protests in 1989.

"Some websites have exploited loopholes in laws and regulations," said Cai Mingzhao, a deputy chief of the State Council Information Office, who chaired the meeting, according to a report on an official news website (www.china.com.cn).

"They have used all kinds of ways to distribute content that is low-class, crude and even vulgar, gravely damaging mores on the Internet."

The Information Office is the government face of the Party's propaganda and censorship machine.

Cai told officials to "fully grasp the gravity and threat of the vulgar current infesting the Internet" and said law-breakers face "stern punishment."

Despite China's rings of censorship, websites and especially blogs have become sometimes racy magnets for the country's nearly 300 million registered Internet users, many in their teens.

The official China Daily reported last month that Shanghai police detained a local woman who became an online sensation after posting a video of herself having sex.

The Financial Times reported on Monday that the Chinese government is arming censors with more advanced filtering software to catch banned content.