Google's threathas heightened fears among Chinese internet users that the country could be on its way out of the global network.

“This is not an issue of Google abandoning China, but one of China abandoning the world,” one prominent blogger, Hecaitou, said on Twitter. Hecaitou's blog was recently blocked in a growingclampdown.

Beijing has increased surveillance and regulation of the web during the past year. Last month, the Ministry for Industry and Information Technology announced that it would start requiring all sites to register their domain names with the government. Analysts say the move could transform China's web into a vast intranet.

It is not yet clear how fully the regulators intend to implement the new rule. But strict enforcement would amount to creating a list of “allowed” websites inside China. It would put all foreign content appearing on domain names registered in other countries out of reach of Chinese users.

“The Chinese are being kept in the internet's Stone Age,” said Xie Wen, a prominent web commentator.

Although Google's China-based service filters its search results according to the requirements of the Chinese government, its self-censorship has been less strict than the one applied on many Chinese search engines or portals.

Observers believe that Beijing would be likely to block Google.com at least partially, as it did before the US company agreed to operate a censored service from servers in China in 2006. If the new rules on domain names are strictly enforced, Google.com and other foreign sites would be totally blacked out.

Mr Xie said: “We are not allowed to play along with web 2.0. Maybe the Chinese will become second-class citizens of the internet world. That is a real possibility. To put it more straightforward, some want to transform the internet into a national intranet.”