BEIJING - Internet giant Google promised Friday to work harder to eliminate pornography from its Chinese Web pages as state media reported authorities had shut down some of its search services.

"Google has continually taken measures against vulgar content, particularly material that is harmful to children, on the Internet in China," a statement by the company said.

"Google is currently stepping up its efforts in this regard."

Xinhua news agency reported that the Chinese agency tasked with fighting online porn has already "stopped some of Google China's searching businesses and asked it to clear up its lewd content."

"Google China was ordered to suspend its overseas web-page searching services and associated word-search services," Xinhua said, citing the China Internet Illegal Information Reporting Centre (CIIRC).

The report gave no other details. Neither Google officials nor the Internet watchdog could immediately be reached to confirm the report.

The centre slammed Google China on Thursday, saying it was continuing to facilitate searches for pornographic material.

"Google China's website has not installed filters to block pornography in accordance with the laws and regulations of our nation," the watchdog said in a statement.

"CIIRC strongly condemns Google China and demands that it thoroughly clean up the pornographic and vulgar content on its sites," it said.

China has vowed to crack down on Internet content that it deems unhealthy, including pornography and information critical of authorities.

Computer makers were notified by the government recently that all personal computers sold from July 1 must be shipped with anti-pornography software, a move that has led to widespread concern both inside and outside China.

China has the world's largest online population at nearly 300 million web users.

Authorities have a history of blocking websites they deem politically unacceptable or offensive, a censorship system that has been dubbed the "Great firewall of China".

Xinhua reported separately on Friday that Beijing plans to recruit an "army of tens of thousands of volunteers" to scour the Internet for porn and report back to authorities in the capital.