Cyber-giant Google — locked in a tug-of-war with China over Internet freedom — has issued a warning to users in the People's Republic that some search words may disrupt connections, and is encouraging them to try other search terms.

A statement posted on Google's website says searches from China have for several years produced results that are, in its words, “inconsistent and unreliable.” The U.S.-based company said it found no problems with its technology, and says extensive research shows that the interruptions are linked to particular words. Beijing has not responded to the accusations.

Google makes no specific mention of China's efforts to filter or block websites critical of the ruling Communist Party, or those that promote gambling, pornography or other content the government finds unacceptable for its 450 million Internet users. But it says that many search terms triggering “error” messages are everyday Chinese characters that have different meanings in different contexts.

Goggle said a team of its engineers reviewed 350,000 of the most popular search queries in China to identify those causing problems. It cites the example of the character for “Jiang,” the surname of a former Chinese president which also means “river.” Goggle did not attempt to reconcile the usages.

But a 2011 health scare surrounding former President Jiang Zemin prompted Beijing to block all related Internet search terms in a push to squelch online speculation of his death.

Users searching for topics such as the 1989 student uprising at Tiananmen Square or Tibet also get error messages — some of them stating “This website is unavailable,” and others stating “The connection was reset.”

Last year, as rumors of President Jiang's death swirled through cyberspace, several search terms on the Twitter-like microblogging site China.com were also blocked. The terms included “301” — the name of the Beijing military hospital where China's top leaders are treated — as well as characters for “brain death” and “brain dead.”

Last month, China's largest microblogging service, Sina Weibo, unveiled a controversial new set of guidelines aimed at officially restricting what its users can post online. The provisions forbid the posting of material that is “untrue,” or information that “threatens the honor of the nation.” They also ban material that “promotes evil teachings” or “destroys societal stability.”

Google relocated its search engine operations from China in 2010, after refusing to self-censor its search content. It redirected such queries to its Hong Kong facilities.