US websites 'hijacked' by Chinese hackers

American websites have come under attack in China since President George W. Bush met the Dalai Lama in Washington this week.

Popular search engines are said to have been "hijacked" by computer hackers who had managed to redirect users to a Chinese website.

Analysts at Search Engine Roundtable, a website focusing on internet searching, said that those attempting to use the search engines on Google, Yahoo and Microsoft websites were being sent on to a Chinese equivalent called Baidu.

Access to other popular American websites including YouTube was also reported to have been blocked.

There was speculation that the motive behind the "hijacking" might be retaliation against the United States for the warm welcome it showed the Dalai Lama.

On Wednesday, Mr Bush called for an end to "religious repression" in China as he defiantly became the first US president to appear in public with the exiled Tibetan spiritual leader.

The Dalai Lama accepted the Congressional Gold Medal, the highest civilian honour awarded by the US, in a formal ceremony in Washington that served to further infuriate Beijing.

"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," said a statement by 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 Dalai Lama.

On Thursday Beijing lodged an official protest over the congressional award, summoning the US ambassador to the foreign ministry.

US officials recently complained of repeated attempts by Chinese hackers to access and disrupt Pentagon and US government websites.