Google confirmed the blocking of its Chinese search engine and Microsoft said it was looking into the matter.
"It seems like China is fed up with the US, so as a way to fight back, they redirected virtually all search traffic from Google, Yahoo and Microsoft to Baidu, the Chinese based search engine," analysts Danny Sullivan and Barry Schwartz wrote at Search Engine Roundtable.
The authors said it was not clear exactly how or why the searches were being redirected, but China is known for tightly controlling the Internet and using a variety of filters to screen out search results for issues relating to dissidents or the 72-year-old Tibetan spiritual leader.
On the Webpronews website, Doug Caverly wrote: "In all likelihood, Baidu, by itself, isn't powerful enough to pull off this switch. Onlookers suspect the Chinese government."
TechCrunch analyst Duncan Riley also cited the "hijacking" and added, "the redirects are more widespread than we first thought" and that the Google-owned video site YouTube also was being blocked.
Digital Market Blog said it was able to confirm the hijacking as well.